WO2001081650A1 - Sputter target, barrier film and electronic component - Google Patents

Sputter target, barrier film and electronic component Download PDF

Info

Publication number
WO2001081650A1
WO2001081650A1 PCT/JP2001/003379 JP0103379W WO0181650A1 WO 2001081650 A1 WO2001081650 A1 WO 2001081650A1 JP 0103379 W JP0103379 W JP 0103379W WO 0181650 A1 WO0181650 A1 WO 0181650A1
Authority
WO
WIPO (PCT)
Prior art keywords
alloy
film
evening
barrier film
target
Prior art date
Application number
PCT/JP2001/003379
Other languages
French (fr)
Japanese (ja)
Inventor
Yukinobu Suzuki
Takashi Ishigami
Yasuo Kohsaka
Naomi Fujioka
Takashi Watanabe
Koichi Watanabe
Kenya Sano
Original Assignee
Kabushiki Kaisha Toshiba
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Kabushiki Kaisha Toshiba filed Critical Kabushiki Kaisha Toshiba
Priority to JP2001578717A priority Critical patent/JP5065565B2/en
Priority to US10/257,404 priority patent/US6750542B2/en
Priority to KR10-2002-7014056A priority patent/KR100504062B1/en
Publication of WO2001081650A1 publication Critical patent/WO2001081650A1/en

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/70—Manufacture or treatment of devices consisting of a plurality of solid state components formed in or on a common substrate or of parts thereof; Manufacture of integrated circuit devices or of parts thereof
    • H01L21/71—Manufacture of specific parts of devices defined in group H01L21/70
    • H01L21/768—Applying interconnections to be used for carrying current between separate components within a device comprising conductors and dielectrics
    • H01L21/76838—Applying interconnections to be used for carrying current between separate components within a device comprising conductors and dielectrics characterised by the formation and the after-treatment of the conductors
    • H01L21/76841—Barrier, adhesion or liner layers
    • H01L21/7687—Thin films associated with contacts of capacitors
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
    • C23C14/06—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material characterised by the coating material
    • C23C14/0641—Nitrides
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
    • C23C14/22—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material characterised by the process of coating
    • C23C14/34—Sputtering
    • C23C14/3407—Cathode assembly for sputtering apparatus, e.g. Target
    • C23C14/3414—Metallurgical or chemical aspects of target preparation, e.g. casting, powder metallurgy
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer
    • H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic System or AIIIBV compounds with or without impurities, e.g. doping materials
    • H01L21/28—Manufacture of electrodes on semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/268
    • H01L21/283—Deposition of conductive or insulating materials for electrodes conducting electric current
    • H01L21/285—Deposition of conductive or insulating materials for electrodes conducting electric current from a gas or vapour, e.g. condensation
    • H01L21/28506—Deposition of conductive or insulating materials for electrodes conducting electric current from a gas or vapour, e.g. condensation of conductive layers
    • H01L21/28512—Deposition of conductive or insulating materials for electrodes conducting electric current from a gas or vapour, e.g. condensation of conductive layers on semiconductor bodies comprising elements of Group IV of the Periodic System
    • H01L21/2855—Deposition of conductive or insulating materials for electrodes conducting electric current from a gas or vapour, e.g. condensation of conductive layers on semiconductor bodies comprising elements of Group IV of the Periodic System by physical means, e.g. sputtering, evaporation
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer
    • H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic System or AIIIBV compounds with or without impurities, e.g. doping materials
    • H01L21/28—Manufacture of electrodes on semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/268
    • H01L21/283—Deposition of conductive or insulating materials for electrodes conducting electric current
    • H01L21/285—Deposition of conductive or insulating materials for electrodes conducting electric current from a gas or vapour, e.g. condensation
    • H01L21/28506—Deposition of conductive or insulating materials for electrodes conducting electric current from a gas or vapour, e.g. condensation of conductive layers
    • H01L21/28512—Deposition of conductive or insulating materials for electrodes conducting electric current from a gas or vapour, e.g. condensation of conductive layers on semiconductor bodies comprising elements of Group IV of the Periodic System
    • H01L21/28568—Deposition of conductive or insulating materials for electrodes conducting electric current from a gas or vapour, e.g. condensation of conductive layers on semiconductor bodies comprising elements of Group IV of the Periodic System the conductive layers comprising transition metals
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L28/00—Passive two-terminal components without a potential-jump or surface barrier for integrated circuits; Details thereof; Multistep manufacturing processes therefor
    • H01L28/40—Capacitors
    • H01L28/55—Capacitors with a dielectric comprising a perovskite structure material
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L28/00—Passive two-terminal components without a potential-jump or surface barrier for integrated circuits; Details thereof; Multistep manufacturing processes therefor
    • H01L28/40—Capacitors
    • H01L28/60—Electrodes
    • H01L28/75—Electrodes comprising two or more layers, e.g. comprising a barrier layer and a metal layer

Definitions

  • the present invention relates to a sputtering target suitable for forming a barrier material on a semiconductor substrate and the like, and a barrier film and an electronic component using the same.
  • ferroelectric memory Recently, storage devices using a ferroelectric thin film as a storage medium, so-called ferroelectric memory (FRAM), have been actively developed. Ferroelectric memories are non-volatile and have the feature that their storage capacity is not lost even after the power is turned off. Furthermore, when the thickness of the ferroelectric thin film is sufficiently small, the spontaneous polarization inversion is fast, and writing and reading can be performed at a speed as fast as DRAM. Since a 1-bit memory cell can be manufactured with one transistor and one ferroelectric capacitor, the ferroelectric memory is also suitable for increasing the capacity.
  • FRAM ferroelectric memory
  • lead zirconate titanate having a belovskite structure solid solution of PbZr ⁇ 3 and PbTi ⁇ 3 (PZT)
  • PZT has features such as high temperature (about 300 ° C) and large spontaneous polarization, but relatively low temperature (about 500 ° C) at which diffusion and evaporation of Pb, the main component, is relatively low. It has a problem that it is easy to occur, and it is said that it is difficult to respond to miniaturization.
  • barium titanate (BaTi ⁇ 3 (BT0)) is known as a typical ferroelectric.
  • BT0 has a lower remanent polarization than PZT, and has a lower Curie temperature (about 120 ° C). It has disadvantages such as a large degree dependency.
  • a BT0 film having a thickness of 60 nm exhibits a Curie temperature of 200 ° C or more by epitaxially growing BTO on a Pt / Mg0 (100) substrate.
  • I have.
  • Such a Ba-rich BSTO film shifts the ferroelectric Curie temperature to a higher temperature side, so that a large remanent polarization is obtained in the room temperature region, and a sufficiently large remanent polarization is obtained even when the temperature is increased to about 85 ° C. Can be held. Therefore, it is possible to realize a ferroelectric film suitable for a storage medium of: FRAM.
  • FRAM ferroelectric film suitable for a storage medium of: FRAM.
  • the Sr-rich BST ⁇ it is necessary to obtain a thin film capacitor with a dielectric constant several times (for example, 800 or more) the dielectric constant of a polycrystalline film when the capacitance is manufactured. Can be.
  • Such dielectric properties are suitable for DRAM.
  • a barrier film include a titanium nitride (TiN) film and a solid solution of TiN and aluminum nitride (A1N) Ti A X A 1 X N (T i -A 1 -N ) The use of membranes is being considered.
  • TiN has a high barrier property to A1 and the like, and is used as a barrier metal in ordinary Si devices. Furthermore, since it is a compound with a high melting point (3000 ° C or higher), its thermal stability is high, and its specific resistance is about 50 / ⁇ ⁇ cm for polycrystalline films and about 18 / ⁇ ⁇ cm for epitaxial films. Therefore, there is an advantage that the contact resistance can be reduced when electric characteristics in the film thickness direction are used.
  • T iN nitrogen oxygen diffuses in T i N on the membrane (N) and oxygen (0) is replaced with an oxide film, other words T i 0 2 is formed.
  • Lower electrode made of P t and SR O is or expansion volume based on the T i 0 2 to produce the T i N membrane surface, adhesion due like that or N 2 gas is generated, Will drop. As a result, there is a problem that the lower electrode is peeled off.
  • JP-A-6-322530 discloses a Ti-A1 alloy evening gate composed only of a diffusion reaction layer of high-purity Ti and high-purity A1.
  • Japanese Patent Application Laid-Open No. 8-134635 discloses that the relative density is 99.0 to 100% and that it is continuous from the surface to the bottom surface in order to improve the wear resistance and oxidation resistance of cutting tools, sliding parts, etc. It shows a Ti-A1 alloy target material without defects.
  • Japanese Patent Application Laid-Open No. 2000-100755 describes a Ti-A1 alloy target for forming a barrier film of a semiconductor device containing 0 in a range of 15 to 900 ppm.
  • Japanese Patent Publication No. 2000-273623 contains 5 to 65 wt% of A1, radioactive elements such as U and Th are O.OOlppm or less, alkali metals such as Na and K are O.lppm or less, and transition metals are If Fe is less than lO.Oppm, 1 ⁇ ; is 5. ( ⁇ 111 or less, C0 is 2.0ppm or less, Cr is 2.0ppm or less, and has a purity of 99.995% or more including its impurities.
  • Japanese Patent Application Laid-Open No. 2000-328242 discloses that an A1 alloy target contains 15 to 40 atomic% of A1 or 55 to 70 atomic% of A1, and has an area ratio of Ti 3 A1 intermetallic compound.
  • A1 alloy target with a metal structure of not less than 30% and defects having a diameter of not less than 0.1 mm and not more than 100 cm2 is described. — One A1 alloy is being offered.
  • the Ti—A 1—N film obtained by subjecting the conventional Ti—A 1 alloy alloy to a chemical sputtering method has a low epitaxial growth property on the Si substrate, As a result, there is a problem that the epitaxial growth of the BT 0 film and the BST 0 film is hindered.
  • FRAM using such a BTO film or a BST0 film cannot obtain sufficient ferroelectric characteristics such as remanent polarization, which degrades FRAM characteristics and manufacturing yield. Similarly, when applied to DRAM, the characteristics and manufacturing yield also decrease.
  • T i one A 1-N although film is essentially have a characteristic called excellent oxidation resistance
  • An object of the present invention is to provide a sputter target capable of forming a Ti—A 1—N film having excellent characteristics and quality as a barrier film with good reproducibility. More specifically, a sputtering target that enables epitaxial growth of the Ti1-A1-N film with good reproducibility, and a sputtering target that enables suppression of dust generation. The purpose is to provide a get. It is another object of the present invention to provide a barrier film and an electronic component having improved characteristics, quality, manufacturing yield, and the like by using such a sputtering target. Disclosure of the invention
  • the present inventors examined the effects of the A1 composition and the crystal grain size of the Ti-A1 alloy on the Ti-A1-N film. As a result, a uniform alloy structure (even-gate structure) is obtained by first dissolving A 1 in the Ti—A 1 alloy in Ti or as an intermetallic compound with Ti. By the way, Ti i A 1—N film It has been found that it is possible to improve the axial growth and to suppress the generation of dust.
  • the present invention has been made based on such findings.
  • the first spa and evening gate of the present invention is a spa and evening gate made of Ti—A1 alloy, wherein A 1 in the Ti—A1 alloy is At least one of a solid solution state and a state in which Ti and an intermetallic compound are formed, and the variation of the A1 content of the entire getter is within 10%. It is characterized by:
  • a second sputter-and-gatherer is a spa gutter composed of a Ti—A1 alloy, wherein A 1 in the Ti—A1 alloy is exists in at least one of a solid solution state and a state in which an intermetallic compound is formed with Ti, and the average crystal grain size of the Ti-A1 alloy is 500 / m or less. In addition, the variation in the crystal grain size of the target as a whole is within 30%.
  • the Ti—A1 alloy preferably contains A1 in the range of 1 to 30 atomic%.
  • the barrier film of the present invention is characterized in that it comprises a Ti-A1-N film formed by using the above-described sputtering target of the present invention.
  • the barrier film of the present invention is suitably used as a barrier material for a semiconductor substrate.
  • An electronic component of the present invention is characterized by including the above-described barrier film of the present invention.
  • Specific examples of the electronic component of the present invention include a semiconductor memory including a semiconductor substrate, a barrier film formed on the semiconductor substrate, and a thin film capacitor formed on the barrier film.
  • FIG. 1 is a sectional view showing a schematic structure of an electronic component according to one embodiment of the present invention.
  • the sputtering target of the present invention is made of a Ti-A1 alloy, and is used, for example, for forming a Ti-A1-N film.
  • a 1 in the Ti—A 1 alloy is a solid solution in Ti or an intermetallic compound with Ti.
  • the intermetallic compound of T i and A 1, T i A l, T i A l 3 s T i A l 2, etc. T i 3 A 1 and the like.
  • a uniform alloy structure can be obtained by causing A1 to exist as a solid solution phase or an intermetallic compound phase.
  • the structure of the target is a uniform solid solution structure of Ti and A1, an intermetallic compound structure of uniform Ti and A1, or a mixed structure of a uniform solid solution and intermetallic compound. be able to.
  • the epitaxial growth of the Ti-A1-N film is improved.
  • a 1 precipitates as a single phase in the Ti—A 1 alloy (spa target), or if A 1 is unbalanced, it will hinder epitaxial growth.
  • a 1 forms a solid solution in Ti up to the solid solubility limit, and the excess exceeds it as an intermetallic compound with Ti.
  • segregation of A1 is likely to occur. In the present invention, precipitation and segregation of A1 are prevented.
  • a 1 in the Ti—A 1 alloy is obtained as a solid solution phase or an intermetallic compound phase. That is, after collecting a test piece from an arbitrary position of the Ti—A1 alloy target, the surface is polished to # 1000 and further puffed. In X-ray diffraction pattern of such a test piece, the peak of substantially T i peak and T i-A 1 intermetallic compound (T i A l, T i A l 3, T i A l 2 , etc.) It only needs to be. In other words, if the peak of A1 does not substantially appear, it is confirmed that A1 exists as at least one of the solid solution phase and the intermetallic compound phase.
  • the effective peak in the X-ray diffraction pattern shall have an intensity ratio of 1/20 or more of the maximum intensity peak.
  • the measurement conditions of X-ray diffraction are as follows: X-ray: Cu, K—H1, voltage: 50 kV, current: 100 mA, vertical goniometer, divergent slit: ldeg, scattered slit: ldeg, light-receiving slit: 0.15mm, scan mode: continuous, scan speed: 5 ° / min, scan step: 0.05 °.
  • the Ti—A1 alloy constituting the sputtering target of the present invention preferably contains A1 in the range of 1 to 30 atomic%.
  • A1 in the range of 1 to 30 atomic%.
  • the amount of A 1 in the target exceeds 30 atomic%, the A 1 that originally forms a solid solution in Ti or forms an intermetallic compound with Ti is simply formed. The risk of precipitation as a phase increases. In other words, segregation of A 1 is likely to occur.
  • a 1 is precipitated as a single phase, the epitaxial growth of the Ti—A 1 —N film is reduced when a Ti—A 1 —N film or the like is formed using a Ti—A 1 alloy alloy gate. I do.
  • the resistivity of the Ti-A1-N film also increases, which causes a deterioration in characteristics as a barrier film.
  • the evening gate structure can be made a uniform solid solution structure of Ti and A1, and a uniform Ti and A 1 or a mixed structure of a uniform solid solution and an intermetallic compound.
  • the obtained Ti—A1—N film can have a uniform solid solution structure of TiN and A1 or a solid solution structure of TiN and A1.
  • l It can be a solid solution structure with N.
  • the amount of A 1 in the Ti-A 1 alloy is less than 1 atomic%, the original effect of improving the oxidation resistance cannot be sufficiently obtained.
  • a Ti—A1—N film formed using a Ti—A1 alloy alloy having an A1 composition of less than 1 atomic percent tends to oxidize and adheres to a film formed thereon. The force is reduced and peeling is liable to occur.
  • the adhesive force between the Ti-A1-N film and the lower electrode of the thin film capacity is reduced.
  • a 1 in the Ti—Al—N film not only increases the oxidation resistance of the film itself, but also functions as a trapping material for oxygen.
  • an electrode film made of a conductive oxide such as SR ⁇ is formed on a Ti—A 1—N film, oxygen in the conductive oxide diffuses into a film formation substrate such as a semiconductor substrate. Is suppressed. From such a point, it is preferable that the amount of A 1 in the Ti-A 1 alloy target is 1 atomic% or more.
  • the A 1 content (Al composition) of the Ti—A 1 alloy that constitutes the sputtering target of the present invention suppresses the oxidation of the barrier film itself more favorably, and furthermore, the epitaxy of the obtained film.
  • the content is more preferably in the range of 1 to 20 atom.%. Further, it is desirable that the A1 composition be in the range of 5 to 15 atomic%.
  • the A1 content of the solid solution in Ti or the existence of an intermetallic compound with Ti was determined.
  • the variation in the evening gate as a whole is within 10%.
  • the variation of the A1 content of the entire target low, a smooth epitaxial growth film can be obtained with good reproducibility. If the variation in the A1 content exceeds 10%, the resulting film has a partially different A1 composition, and thus, for example, a difference occurs in the crystal growth properties of Ti—A1—N, and Epitaxial growth will be reduced.
  • the variation in the A1 content of the entire evening gate is more preferably 5% or less, and further preferably 1% or less.
  • the variation in the A1 content of the entire evening gate indicates a value obtained as follows.
  • each position is 10% from the center of the target and the outer circumference of two straight lines that pass through the center and divide the circumference evenly (total of 5 points including the center)
  • Samples were taken from each sample, and the A1 content of these five test pieces was measured ten times, and the average of these ten measurements was taken as the A1 content of each test piece. .
  • a variation [%] specified in the present invention is calculated based on the formula of ⁇ (maximum value-minimum value) / (maximum value + minimum value) ⁇ ⁇ 100.
  • the A1 content is a value measured by a commonly used inductively coupled plasma emission spectroscopy.
  • the sputtering target of the present invention is made of a high-purity Ti—A1 alloy.
  • oxygen is particularly present.
  • the average oxygen content of the Ti-A1 alloy is 900 ppm or less in order to reduce the epitaxial growth of the obtained Ti-Al-N film. It is preferable that oxygen promotes the oxidation of the resulting Ti-A1-N film and reduces the adhesion of the film formed thereon (eg, the lower electrode of the thin film capacitor). From such a point, the average oxygen content of the Ti-A1 alloy is preferably 900 ppm or less.
  • the barrier properties of the resulting Ti—A1—N film may be reduced.
  • the Ti-A1 alloy should preferably contain oxygen in the range of 10 to 500 ppm. A more preferred oxygen content is in the range of 50-400 ppm. Such an amount of oxygen effectively functions for the barrier property of the Ti-A1N film.
  • the variation in the oxygen content in the Ti—A1 alloy evening get be within 30% as a whole.
  • the variation in the oxygen content of the entire target is to be determined in the same manner as the variation in the A1 content described above.
  • the oxygen content shall be the value measured by the commonly used inert gas fusion infrared absorption method.
  • the impurity elements other than oxygen in the spa bath and gate (Ti-A1 alloy bath) of the present invention are slightly different from those of general high-purity metal materials. May be included. However, it is preferable to reduce the amount of other impurity elements in order to improve the epitaxial growth property as in the case of oxygen.
  • the average grain size (average crystal grain size) of the crystal grains constituting the Ti-A1 alloy is preferably not more than 50 ⁇ £ ⁇ . Further, it is preferable that the variation of the crystal grain size of the whole evening target is within 30%.
  • the generation of dust can be suppressed by making the crystal grains forming the Ti-A1 alloy alloy relatively fine and reducing the variation in the crystal grain size of the entire target.
  • dust is a type of flakes generated when particles scattered by sputtering adhere to the non-erosion area of the protection plate or the sunset placed in the sputter device and are separated. Discharge occurs due to abnormal electric discharge caused by the potential difference generated in the gap between crystal grains, and molten particles called splash generated based on this. In any case, it usually indicates a size of about 0.2 to 0.3 / m.
  • the dust that is suddenly generated from the conventional Ti—A1 alloy one-gap is larger than 1 m, which is 1 m or more.
  • the shape is also massive like rock. This massive dust has a mode in which a part of the crystal grains or the crystal grains themselves are extracted by sputtering. If the crystal grain size of the target as a whole varies, the incidence of such a huge dust increases.
  • the average crystal grain size of the Ti-A1 alloy target is set to 500 m or less and the variation of the crystal grain size of the entire target to 30% or less, thermal stress, etc. It is possible to suppress the scattering of a part of the crystal grains or the crystal grains themselves due to the influence of. As a result, generation of giant dust is suppressed, and the yield of the Ti-A1-N film can be significantly improved.
  • the grain size of the Ti—A1 alloy is preferably 300 m or less, more preferably 200 zm or less. Further, the variation in the crystal grain size of the entire evening target is more preferably within 15%, and further preferably within 10%. As described above, a uniform solid solution structure in which A1 is dissolved in Ti and a uniform intermetallic compound structure of Ti and A1 also have an effect on suppression of giant dust.
  • the number B of crystal grains is converted to 1/2, and the total number n of crystal grains in a circle is set to A + B / 2. From the total number n of crystal grains in this circle, the measurement magnification M, and the area A (mm2) of the circle,
  • the variation in the crystal grain size of the entire evening-get is the central part of the evening-get, the position near each outer circumference on two straight lines passing through the center and dividing the circumference equally, and 1/2 of that Test specimens were taken from each position at the distance (a total of 9 places including the center), and the average crystal grain size of these 9 test specimens was measured 10 times by the above method.
  • the average value of the measured values shall be the crystal grain size of each test piece. Then, from the maximum value and the minimum value of these measured values, based on the formula of ⁇ (maximum value-minimum value) / (maximum value + minimum value) ⁇ X100, the variation of the crystal grain size defined by the present invention [% ].
  • the test piece shall be 10 mm long and 10 mm wide.
  • the manufacturing method of the sputter bath of the present invention is not particularly limited, but it is preferable to manufacture it by applying a dissolving method as described below. It is preferable to reduce the variation in the A1 content by controlling.
  • the Ti-A1 alloy ingot is produced by melting.
  • the cold wall melting method by controlling the melting conditions, segregation of A1 can be suppressed and a uniform alloy structure can be obtained with good reproducibility.
  • the cold wall melting method is also effective in reducing impurity elements and their variations.
  • a solution treatment at a temperature in the range of 80 to 90% of the melting point of the Ti-A1 alloy in order to reduce variation in the A1 content.
  • the solution treatment is preferably performed for 24 hours or more in a vacuum of less than lxlO_lPa or in an Ar atmosphere.
  • Such a solution treatment is effective not only in suppressing the variation in the A1 content but also in reducing the variation in the oxygen content, miniaturizing and averaging the crystal grain size.
  • the solution treatment temperature is preferably set to a temperature in the range of 80 to 90% of the melting point of the Ti-A1 alloy. More preferred temperatures are in the range of 85-90% of the melting point.
  • T i—A 1 Since gold is easily oxidized, the pressure at that time should be 1 X 10 1 lPa or less. Further, if the solution treatment time is too short, the dispersion effect of A1 becomes insufficient, so that the time is preferably at least 24 hours.
  • the melting method and the EB melting method it is preferable to perform the melting several times (for example, two to three times) because there is a high possibility that A1 may be biased. Thus, segregation of A1 can be reduced by performing arc melting and EB melting several times.
  • the processing rate at this time is, for example, 60 to 95%.
  • an appropriate amount of thermal energy can be given to the ingot, and the energy can be used to homogenize A1 and oxygen. If the processing rate is too high, cracks are likely to occur during processing. Conversely, if the working ratio is too low, recrystallization in the subsequent steps will be insufficient. For this reason, it is preferable that the working ratio during plastic working be in the range of 60 to 95%.
  • a more preferable processing rate is in the range of 70 to 90%, and further preferably, in the range of 80 to 90%.
  • the alloy material is annealed at a temperature of 900 to 1200 ° C and recrystallized.
  • the average crystal grain size and its variation can be controlled within the scope of the present invention. If the annealing temperature is too high, the size of the recrystallized grains becomes too large. Conversely, if the annealing temperature is too low, recrystallization will be insufficient. Therefore, the annealing temperature is preferably in the range of 900 to 1200 ° C.
  • the preferred annealing temperature is in the range of 950 to 1150 ° C, and more preferably in the range of 1000 to 1100 ° C.
  • the evening-get material consisting of the Ti-A1 alloy obtained by the above-mentioned melting method is machined into the desired evening-get shape and made of, for example, A1 or Cu.
  • the desired sputter and evening gate can be obtained.
  • Diffusion bonding, brazing bonding using at least one of In, Zn and Sn, or a brazing material containing them can be employed for bonding to the backing plate.
  • an integrated sputter plate that simultaneously forms the backing plate shape when the spatter plate is manufactured may be used.
  • Baria film of the present invention uses Supadzu evening evening one gate Uz city of the present invention described above (T i one A 1 alloy evening one rodents g), for example, by A r and mixing by reduction phase sputtering evening gas N 2 those having a film-formed T i-a l-N film (T i i- x a 1 ⁇ ⁇ film (0. 01 ⁇ 0.3)).
  • the Ti—A1N film obtained in this way has excellent EB growth on semiconductor substrates such as Si substrates, has good properties as a barrier film, and greatly reduces the number of dusts generated. It is a thing.
  • a barrier film (Ti—Al—N film) having excellent characteristics and quality can be obtained with good yield.
  • the Ti-A1-N film of the present invention has an excellent barrier property against various elements such as Sr and Ba, and has a low resistance such as a resistivity of ⁇ 'cm or less. Therefore, by using such a Ti—A 1—N film as a barrier film between the semiconductor substrate and various elements, the mutual diffusion between the semiconductor substrate and the element constituent layer can be favorably suppressed. . Furthermore, since oxidation of the Ti—A 1—N film due to high-temperature annealing (for example, at 600 ° C. or higher) can be prevented, the adhesive force at the interface between the Ti—A 1—N film and the element constituent layer can be reduced. It is possible to suppress the decrease. That is, it is possible to suppress peeling of the element constituent layer on the Ti-Al-N film. Furthermore, since the epitaxial growth of the element configuration layer is not hindered, The characteristics can be improved.
  • the Ti-Al-N film described above is suitable as a barrier material for a semiconductor substrate.
  • a barrier film of the present invention can be used for various electronic components. Specifically, semiconductors such as FRAMs and DRAMs, which combine a semiconductor substrate on which a switch transistor is formed and a thin film capacitor (memory cell) using a dielectric thin film made of perovskite oxide For memories, the barrier film of the present invention is effectively used.
  • FIG. 1 is a sectional view schematically showing a capacity portion of a semiconductor memory as one embodiment of an electronic component of the present invention.
  • reference numeral 1 denotes a semiconductor substrate (Si substrate) on which a switching transistor (not shown) is formed.
  • the above-described Ti—Al—N film (T i i- ⁇ 1 ⁇ ⁇ film (0.01 ⁇ ⁇ 0.3)) of the present invention is formed as a barrier film 2.
  • a thin film capacitor 3 is formed on top of it.
  • the thin film capacitor 3 has a lower electrode 4, a dielectric thin film 5, and an upper electrode 6 formed on the barrier film 2 in order.
  • the lower electrode 4 includes noble metals such as Pt, Au, Pd, Ir, Rh, R ⁇ , and Ru, and alloys thereof (such as Pt—Rh and Pt—Ru), or S r R u 0 3, C a R u 0 3 ⁇ B a R u 0 3 and their solid solution system (e.g. (B a, S r) R ⁇ 3 and (S r, C a) R u 0 3)
  • a conductive perovskite oxide such as is used.
  • the constituent material of the upper electrode 6 is not particularly limited, but it is preferable to use a noble metal (including an alloy) or a conductive perovskite oxide similar to the lower electrode 4.
  • a dielectric material having a bevelskite-type crystal structure is preferable.
  • An example of such a dielectric material is a perovskite oxide represented by AB03.
  • barium titanate (B a T i 0 3 ( BT 0)) was used as a main component, a part of the A site elements (B a) Is replaced by an element such as Sr or Ca, or a perovskite oxide (BSTO) in which part of the B-site element (T i) is replaced by an element such as Zr, Hf, or Sn.
  • BSTO perovskite oxide
  • Berovskite-type oxides mainly composed of BTO become ferroelectric or paraelectric depending on the amount of substitution of the B-site element and the A-site element and the amount of strain based on lattice strain. Therefore, by appropriately setting the composition and the amount of strain of the perovskite oxide, the dielectric thin film 5 corresponding to the intended use of the thin film capacitor 3 can be obtained.
  • Berobusukai preparative oxides other than B T0 and BST 0 is the dielectric thin film 5, for example, S r T I_rei_3, C a T I_rei_3, simple, such as B a S n0 3, B a Z r 03 base Ropusukai preparative oxide, B a (M i / 3 Nb 2/3) ⁇ 3, B a (Mgi / 3 T a 2/3) 0 3 composite base Ropusukai preparative oxides such as, and these solid It is also possible to apply a solution system or the like. It goes without saying that a slight deviation from the stoichiometric ratio is permissible for the composition of the perovskite oxide.
  • the thin film capacity 3 can be improved on the semiconductor substrate 1 without deteriorating its characteristics by the barrier film 2 composed of a Ti-A1-N film having excellent barrier characteristics and oxidation resistance. It becomes possible to form it. In particular, peeling between the lower electrode 4 of the thin film capacitor 3 and the barrier film 2 can be favorably suppressed.
  • the thickness of the barrier layer 2 is preferably as thin as possible within a range in which the effect of preventing diffusion can be obtained, and specifically, is preferably in the range of 10 to 50 mn.
  • the Ti—A 1—N film as the Noria film 2 is grown by epitaxial growth.
  • a ferroelectric property or a high dielectric property induced by strain introduced during epitaxial growth is used. It is possible to produce a thin film capacitor on the semiconductor substrate 1 with good film quality. Therefore, by highly integrating such a thin film capacity and a transistor on a semiconductor substrate, highly practical and highly reliable semiconductor memories such as FRAM and DRAM can be manufactured with high yield.
  • each of the above-mentioned alloy ingots was subjected to hot rolling at a working rate shown in Table 1 at 1000 ° C and then reannealed at 900 ° C for 1 hour. After grinding and polishing each alloy material after recrystallization, it is diffusion bonded by A1 backing plate and hot press, and further machined to obtain a Ti—A1 with a diameter of 320 mm and a thickness of 10 thighs. Alloy evening gates were made individually.
  • each Ti-A1 alloy obtained in this manner was performed.
  • the X-ray diffraction pattern showed that the Ti peak and the Ti-A1 metal It was confirmed that only the peak of the inter-compound appeared. That is, each i-A1 alloy alloy had a uniform structure consisting of a Ti-A1 solid solution and a Ti-A1 intermetallic compound structure. Further, the variation in the A1 content, the average oxygen content, and the variation in the oxygen content of each of these Ti_A1 alloy targets were measured in accordance with the above-described methods. Table 1 shows the measurement results.
  • each Ti-A1 alloy target had a uniform structure consisting of a Ti-A1 solid solution and a Ti-A1 intermetallic compound structure. Further, the variation in the A1 content, the average oxygen content, and the variation in the oxygen content of each of these Ti—A1 alloy targets were measured in accordance with the above-described methods. Table 2 shows the measurement results. Table 2
  • each Ti—A1 alloy target had a uniform structure consisting of a Ti—A1 solid solution and a Ti—A1 intermetallic compound structure. Further, the variation in the A1 content, the average oxygen content, and the variation in the oxygen content of each of these Ti_A1 alloy targets were measured in accordance with the above-described methods. Table 3 shows the measurement results. Table 3
  • a Ti-A1 alloy evening gate was produced in the same manner as in Example 1 except that a densified sintered Ti—A1 alloy material (sintered body) was used. did.
  • Comparative Examples 2 and 3 except that the number of times of the arc melting or the EB melting was set to one each, in the same manner as in Sample No. 13 of Example 2 and Sample No. 3 of Example 3, the T i—A 1 alloy evening gate Made.
  • Comparative Example 4 a Ti—A1 alloy target was produced in the same manner as in Sample No. 9 of Example 1, except that the solution treatment was not performed by the cold wall method.
  • the variation in the A1 content, the average oxygen content, and the variation in the oxygen content of each Ti-A1 alloy according to Comparative Examples 1 to 4 were measured in accordance with the above-described method. Table 4 shows the measurement results. Table 4
  • Ti—A1N The film was formed to a thickness of about 10 to 100 nm.
  • the S i (100) substrate used was a surface etched with a 1% HF solution for 3 minutes and rinsed off with ultrapure water for 30 minutes.
  • the number of Si substrates on which the Ti—Al—N films were formed was 500 each.
  • each Ti-Al_N film thus formed was confirmed by RHEED (Reflection High Energy Electron Diffrection) installed in a vacuum chamber. That is, it was determined from the RHEED diffraction pattern whether the film was an epitaxy film or not.
  • RHEED Reflect High Energy Electron Diffrection
  • Table 5 summarizes the results. The values in Table 5 show the number of epitaxially grown sheets out of 500 sheets as a percentage (%).
  • each of the Ti—A 1—N films described above was used as a barrier film, and a Pt film was formed thereon using an RF magneto aperture (substrate temperature: 500 ° C.) to form a lower electrode.
  • the thickness of the Pt film was about 100 nm.
  • a B a T i 0 3 film as a dielectric film was formed by RF magnetic Tron Supadzu evening that.
  • the substrate temperature was set to 600 ° C., and the temperature of the gas was 02 100%.
  • the Ti_A1-N films formed by using each of the sputtering targets according to Examples 1 to 3 have excellent epitaxy growth properties, and a T i 0 3 film can be seen also favorably can be E peak evening press Le grown for. Further, in Examples 1 to 3, It has neither the B a T i 0 3 film has good residual polarization due is sure Kuchishin.
  • High purity Ti and A1 pieces were melted by the cold wall melting method to produce a plurality of alloy ingots (diameter: 75 to 105 mm) with A1 content of 9 atomic%. Next, these alloy ingots were subjected to hot rolling (working rate 80%) at 1000 ° C, and then annealed for 1 hour at the temperatures shown in Table 2 for recrystallization. .
  • Each of these alloy ingots is ground and polished, and then diffusion bonded by a hot press and an A1 backing plate, and further machined to produce a Ti-A1 alloy with a diameter of 320 mm and a thickness of 10 mm. I made one gate each.
  • each Ti-A1 alloy target had a uniform structure consisting of a Ti-A1 solid solution and a Ti-A1 intermetallic compound structure, as in Example 1. Further, the variation of the A1 content was the same as in Example 1.
  • a Ti-A1-N film is formed on the Si (100) substrate by chemical phase sputtering to a thickness of about 10 to 100 nm. Filmed.
  • the film forming conditions for the Ti—A 1—N film are as described above.
  • the number of Si substrates was 500 each.
  • the number of dust having a size of l ⁇ m or more present in each Ti-A1-N film thus obtained was measured by particle counting. The results are shown in Table 6.
  • the number of dust in Table 6 is the average value of 500 pieces.
  • the crystallinity of each film was confirmed by RHEED installed in the vacuum chamber. It was a diffraction pattern of the epitaxial film, and a streak was observed, confirming that a smooth epitaxial film was formed.
  • the sputtering apparatus of the present invention it is possible to form a Ti-A1-N film having excellent characteristics and quality as a parier film with good reproducibility. It becomes possible. Therefore, by using such a barrier film composed of the Ti—A 1—N film, it is possible to improve the characteristics and yield of various electronic components.
  • the barrier film of the present invention is particularly suitable for FRAM and DRAM using a perovskite oxide film as a dielectric film.

Abstract

A sputter target comprising a Ti-Al alloy containing 1-30 atm% of Al, wherein Al exists in at least one of solid solution state in Ti or a state forming an intermetallic compound with Ti and variation in the content of Al is limited to within 10% for the entire target. Furthermore, the Ti-Al alloy has average crystal grain size of 500 µm or less and variation of crystal grain size is limited to within 30% for the entire target. A Ti-Al-N film is formed as a barrier film using a sputter target comprising such a Ti-Al alloy. An electronic component comprises a barrier film formed on a semiconductor substrate.

Description

明 細 書 スパッ夕夕一ゲッ ト、 バリア膜および電子部品 技術分野  SPECIFICATIONS SPECIAL PARTS, barrier films and electronic components
本発明は、 半導体基板などに対するバリァ材の形成に好適なスパッ夕 夕一ゲッ トと、 それを用いたバリァ膜および電子部品に関する。 背景技術  The present invention relates to a sputtering target suitable for forming a barrier material on a semiconductor substrate and the like, and a barrier film and an electronic component using the same. Background art
最近、 記憶媒体として強誘電体薄膜を用いた記憶装置、 いわゆる強誘 電体メモリ （F RAM) の開発が盛んに行われている。 強誘電体メモリ は不揮発性であり、 電源を落とした後も記憶容量が失われないという特 徴を有する。 さらに、 強誘電体薄膜の膜厚が十分に薄い場合には、 自発 分極の反転が速く、 D RAM並みの髙速の書き込みおよび読み出しが可 能である。 1 ビヅ トのメモリセルを 1つのトランジスタと 1つの強誘電 体キャパシ夕で作製することができることから、 強誘電体メモリは大容 量化にも適している。  Recently, storage devices using a ferroelectric thin film as a storage medium, so-called ferroelectric memory (FRAM), have been actively developed. Ferroelectric memories are non-volatile and have the feature that their storage capacity is not lost even after the power is turned off. Furthermore, when the thickness of the ferroelectric thin film is sufficiently small, the spontaneous polarization inversion is fast, and writing and reading can be performed at a speed as fast as DRAM. Since a 1-bit memory cell can be manufactured with one transistor and one ferroelectric capacitor, the ferroelectric memory is also suitable for increasing the capacity.
強誘電体材料としては、 主としてベロブスカイ ト型構造を有するジル コン酸チタン酸鉛 （P b Z r〇3 と P b T i〇3 の固溶体 （P Z T) ) が用いられている。 しかし、 P Z Tはキユリ一温度が高い （ 300°C程 度） 、 自発分極が大きいなどの特徴を有する反面、 主成分である P bの 拡散および蒸発が比較的低い温度 （500°C程度） で起こ りやすいという 問題を有しており、 微細化には対応しにくいと言われている。 P Z T以 外ではチタン酸バリウム （B a T i〇3 (B T 0) ) が代表的な強誘電 体として知られている。 しかし、 B T 0は P Z Tと比べて残留分極が小 さく、 しかもキュリー温度が低い （120°C程度） ために、 残留分極の温 度依存性が大きいなどの難点を有している。 As the ferroelectric material, lead zirconate titanate having a belovskite structure (solid solution of PbZr〇3 and PbTi〇3 (PZT)) is mainly used. However, PZT has features such as high temperature (about 300 ° C) and large spontaneous polarization, but relatively low temperature (about 500 ° C) at which diffusion and evaporation of Pb, the main component, is relatively low. It has a problem that it is easy to occur, and it is said that it is difficult to respond to miniaturization. Other than PZT, barium titanate (BaTi〇3 (BT0)) is known as a typical ferroelectric. However, BT0 has a lower remanent polarization than PZT, and has a lower Curie temperature (about 120 ° C). It has disadvantages such as a large degree dependency.
これに対して、 P t /M g 0 (100)基板上に B T Oをェピタキシャル 成長させることによって、 例えば膜厚 60nm の B T 0膜が 200°C以上の キュリー温度を示すことが見出されている。 さらに、 P tやルテニウム 酸ス トロンチウム （ S r R u 03 ( S R O) ) からなる下部電極上に、 チタン酸バリ ウムス トロンチウム （ B aaS r卜 aT i 〇 3 ( B S T 〇） ) をェピタキシャル成長させると、 本来強誘電性を示さないはずの 組成領域 （a≤0.7) で強誘電性が発現することが確認されている。 これ は； B S T O結晶の c軸方向の格子が伸長することに由来する。 On the other hand, it has been found that, for example, a BT0 film having a thickness of 60 nm exhibits a Curie temperature of 200 ° C or more by epitaxially growing BTO on a Pt / Mg0 (100) substrate. I have. Furthermore, E on the lower electrode made of P t and ruthenium Sanz strontium (S r R u 03 (SRO )), titanate burr Umusu strontium (B a a S r Bok a T i 〇 3 (BST 〇)) and It has been confirmed that ferroelectricity develops in a composition region (a≤0.7) that should not exhibit ferroelectricity by epitaxial growth. This is due to the fact that the lattice in the c-axis direction of the BSTO crystal is elongated.
このような B aリッチの B S T O膜は、 強誘電キュリー温度が高温側 にシフ トするため、 室温領域で大きな残留分極が得られ、 かつ 85°C程 度まで温度を上げても十分大きな残留分極を保持することができる。 従って、 ： F R A Mの記憶媒体に好適な強誘電体膜を実現することが可能 となる。 一方、 S r リ ッチの B S T〇を用いた場合には、 多結晶膜で キャパシ夕を作製したときの誘電率の数倍 （例えば 800以上） に達する 誘電率を有する薄膜キャパシ夕を得ることができる。 このような誘電特 性は D RAMに好適である。  Such a Ba-rich BSTO film shifts the ferroelectric Curie temperature to a higher temperature side, so that a large remanent polarization is obtained in the room temperature region, and a sufficiently large remanent polarization is obtained even when the temperature is increased to about 85 ° C. Can be held. Therefore, it is possible to realize a ferroelectric film suitable for a storage medium of: FRAM. On the other hand, when the Sr-rich BST〇 is used, it is necessary to obtain a thin film capacitor with a dielectric constant several times (for example, 800 or more) the dielectric constant of a polycrystalline film when the capacitance is manufactured. Can be. Such dielectric properties are suitable for DRAM.
上述したように、 ェピタキシャル成長させた； B T 0膜や B S T 0膜な どを有する薄膜キャパシ夕を用いて、 F RAMや D RAMなどの半導体 メモリを実用化することが期待されている。 これらを実用化するにあ たっては、 スィ ヅチ用トランジスタを形成した半導体基板とぺロプス力 イ ト型酸化物膜を用いたメモリセル （薄膜キャパシ夕） とを組合せる必 要がある。 この際、 薄膜キャパシ夕の下部電極や誘電体薄膜を構成する P t、 R u、 S r s B aなどの元素がトランジスタ中に拡散すると、 ス ィツチング動作に悪影響を及ぼすという問題がある。  As described above, it is expected that semiconductor memories such as FRAM and DRAM will be put to practical use by using a thin-film capacitor having an epitaxially grown BT0 film and a BST0 film. In order to put these into practical use, it is necessary to combine a semiconductor substrate on which a switching transistor is formed with a memory cell (thin film capacity) using a low-power oxide film. At this time, if elements such as Pt, Ru, and SrsBa constituting the lower electrode of the thin film capacitor and the dielectric thin film diffuse into the transistor, there is a problem that the switching operation is adversely affected.
このようなことから、 半導体基板との間には相互拡散を防ぐバリァ膜 を形成する必要がある。 さらに、 上述したようなェピタキシャル効果を 得るためには、 バリア膜自体を半導体基板上にェピタキシャル成長させ る必要がある。 このようなバリァ膜としては、 窒化チ夕ン （T i N) 膜 や T i Nと窒化アルミニウム （A 1N) との固溶体である T iレ XA 1 XN (T i -A 1 -N) 膜を用いることが検討されている。 For this reason, a barrier film that prevents interdiffusion with the semiconductor substrate Need to be formed. Further, in order to obtain the above-mentioned epitaxy effect, it is necessary to grow the barrier film itself on the semiconductor substrate by epitaxy. Examples of such a barrier film include a titanium nitride (TiN) film and a solid solution of TiN and aluminum nitride (A1N) Ti A X A 1 X N (T i -A 1 -N ) The use of membranes is being considered.
T i Nは A 1などに対するバリァ性が高く、 通常の S iデバイスにお いてもバリアメタルとして利用されている。 さらに、 高融点の化合物 (3000°C以上） であるために熱的安定性も高く、 また比抵抗が多結晶膜 で 50 / Ω · cm程度、 ェピタキシャル膜で 18 / Ω · cm程度と非常に低い ことから、 膜厚方向の電気特性を利用する場合にコンタク ト抵抗が下げ られるという利点がある。  TiN has a high barrier property to A1 and the like, and is used as a barrier metal in ordinary Si devices. Furthermore, since it is a compound with a high melting point (3000 ° C or higher), its thermal stability is high, and its specific resistance is about 50 / Ω · cm for polycrystalline films and about 18 / Ω · cm for epitaxial films. Therefore, there is an advantage that the contact resistance can be reduced when electric characteristics in the film thickness direction are used.
しかしながら、 薄膜キャパシ夕のバリア膜として T i Nを用いた場 合、 素子製造工程中に例えば強誘電体膜の結晶制御のために実施される 高温下 （例えば 600°C以上） でのァニールによって、 T iN膜上に酸素 が拡散して T i N中の窒素 （N) と酸素 （0) が置換して酸化膜、 つま り T i 02 が形成されてしまう。 P tや SR Oなどからなる下部電極 は、 T i N膜表面に生成する T i 02 に基づいて体積が膨張したり、 ま た N2 ガスが発生することなどに起因して付着力が低下してしまう。 そ の結果として、 下部電極に剥がれが生じてしまうという問題がある。 一方、 T i Nに A 1を添加して T i i-xA 1 XN (T i -A 1 -N) 膜 とすることで耐酸化性を高めることができる。 丄ー八丄—！^膜は、 T i 1-χΑ 1 χ 合金 （T i— A 1合金） ターゲッ トを用いて、 アルゴンHowever, when TiN is used as a barrier film for a thin film capacitor, annealing at a high temperature (for example, 600 ° C or more) performed during the device manufacturing process, for example, to control the crystal of a ferroelectric film. , T iN nitrogen oxygen diffuses in T i N on the membrane (N) and oxygen (0) is replaced with an oxide film, other words T i 0 2 is formed. Lower electrode made of P t and SR O is or expansion volume based on the T i 0 2 to produce the T i N membrane surface, adhesion due like that or N 2 gas is generated, Will drop. As a result, there is a problem that the lower electrode is peeled off. On the other hand, it is possible to improve the oxidation resistance by the T i N in the addition of A 1 T i i- x A 1 X N (T i -A 1 -N) film.丄 ー 八 丄 —! ^ The film is made of argon using a Ti 1-χΑ 1 合金 alloy (Ti-A 1 alloy) target.
(Ar) および窒素 （N) 雰囲気中で化相スパッ夕することにより形成 される。 T i一 A 1合金夕ーゲヅ トに関して、 例えば特開平 6-322530 号公報には高純度 T iと高純度 A 1との拡散反応層のみで構成された T i一 A 1合金夕一ゲヅ 卜が記載されている。 また、 特開平 8-134635 号公報には、 切削工具ゃ摺動部品などの耐摩 耗性ゃ耐酸化性の向上を目的として、 相対密度が 99.0〜100%であり、 かつ表面から底面まで連続した欠陥が無い T i一 A 1合金ターゲッ ト材 が記載されている。 特開 2000-100755号公報には、 0を 15〜900ppmの 範囲で含有する半導体装置のバリア膜形成用 T i一 A 1合金ターゲッ ト が記載されている。 It is formed by spattering the chemical phase in an atmosphere of (Ar) and nitrogen (N). Regarding the Ti-A1 alloy evening gate, for example, JP-A-6-322530 discloses a Ti-A1 alloy evening gate composed only of a diffusion reaction layer of high-purity Ti and high-purity A1. Are described. Japanese Patent Application Laid-Open No. 8-134635 discloses that the relative density is 99.0 to 100% and that it is continuous from the surface to the bottom surface in order to improve the wear resistance and oxidation resistance of cutting tools, sliding parts, etc. It shows a Ti-A1 alloy target material without defects. Japanese Patent Application Laid-Open No. 2000-100755 describes a Ti-A1 alloy target for forming a barrier film of a semiconductor device containing 0 in a range of 15 to 900 ppm.
さらに、 特閧 2000- 273623号公報には A 1を 5〜65wt%含有し、 U、 Thなどの放射性元素が O.OOlppm 以下、 Na、 Kなどのアルカリ金属 が O.lppm以下、 遷移金属である Feが lO.Oppm以下、 1^ ;[が 5.(^ 111以 下、 C 0が 2.0ppm以下、 C rが 2.0ppm以下であり、 その不純物を含め て 99.995 %以上の純度を有する T i一 A 1合金ターゲッ トが、 特開 2000- 328242号公報には A 1を 15〜40原子％、 あるいは A 1を 55〜70 原子％含有し、 T i3A 1金属間化合物の面積率が 30%以上である金属 組織を有し、 かつ径が 0.1mm以上の欠陥が 10個ノ 100cm2以下である T i— A 1合金ターゲッ トが記載されている。 このように、 各種の T i— A 1合金夕一ゲッ トが閧発されている。 Furthermore, Japanese Patent Publication No. 2000-273623 contains 5 to 65 wt% of A1, radioactive elements such as U and Th are O.OOlppm or less, alkali metals such as Na and K are O.lppm or less, and transition metals are If Fe is less than lO.Oppm, 1 ^; is 5. (^ 111 or less, C0 is 2.0ppm or less, Cr is 2.0ppm or less, and has a purity of 99.995% or more including its impurities. Japanese Patent Application Laid-Open No. 2000-328242 discloses that an A1 alloy target contains 15 to 40 atomic% of A1 or 55 to 70 atomic% of A1, and has an area ratio of Ti 3 A1 intermetallic compound. A1 alloy target with a metal structure of not less than 30% and defects having a diameter of not less than 0.1 mm and not more than 100 cm2 is described. — One A1 alloy is being offered.
しかしながら、 従来の T i一 A 1合金夕一ゲッ トを化相スパッ夕する ことにより得られた T i— A 1—N膜は、 S i基板に対するェピ夕キ シャル成長性が低く、 その結果として B T 0膜や B S T 0膜のェピタキ シャル成長が阻害されるという問題がある。 このような BTO膜や B S T 0膜を使用した F RAMでは、 残留分極などの強誘電特性を十分に得 ることができず、 F R AMの特性や製造歩留りを低下させることにな る。 DRAMに適用した場合においても、 同様に特性や製造歩留りの低 下を招くことになる。  However, the Ti—A 1—N film obtained by subjecting the conventional Ti—A 1 alloy alloy to a chemical sputtering method has a low epitaxial growth property on the Si substrate, As a result, there is a problem that the epitaxial growth of the BT 0 film and the BST 0 film is hindered. FRAM using such a BTO film or a BST0 film cannot obtain sufficient ferroelectric characteristics such as remanent polarization, which degrades FRAM characteristics and manufacturing yield. Similarly, when applied to DRAM, the characteristics and manufacturing yield also decrease.
さらに、 従来の T i - A 1合金夕一ゲヅ トを用いて、 化相スパヅ夕で T i - A 1—N膜を成膜した場合、 スパッ夕成膜中に突発的に巨大なダ ス トが発生しやすく、 その結果として F R A Mや D R A Mの製造歩留り を低下させるという問題がある。 このような問題は薄膜キャパシ夕のバ リア膜として T i— A 1— N膜を利用する場合に限らず、 通常の半導体 素子のバリァ膜として T i一 A 1— N膜を使用した場合にも同様に問題 となる。 Furthermore, when a Ti-A1-N film is formed at a chemical vapor phase using a conventional Ti-A1 alloy alloy gate, a huge gigantic suddenly occurs during the sputter deposition. There is a problem that the cost is likely to occur, and as a result, the manufacturing yield of FRAM and DRAM is reduced. Such a problem is not limited to the case where a Ti—A 1—N film is used as a barrier film of a thin film capacitor, but also when a Ti—A 1—N film is used as a barrier film of an ordinary semiconductor device. Is also a problem.
上述したように、 T i一 A 1— N膜は本質的には耐酸化性に優れると いう特性を有しているものの、 その形成に使用する T i ! _XA 1 χ合金 夕ーゲツ トの組成や性状などについては必ずしも十分に検討されている とは言えない。 このため、 S i基板に対する T i— A 1— Ν膜のェビ夕 キシャル成長性が低下したり、 さらには巨大ダス トが突発的に発生する というような問題などを招いている。 As described above, T i one A 1-N although film is essentially have a characteristic called excellent oxidation resistance, T i! _ X A 1 χ alloy evening Getsu you want to use for the formation It cannot be said that the composition, properties, etc. of these have not been sufficiently studied. For this reason, the epitaxial growth of the Ti—A 1—Ν film on the Si substrate is reduced, and further, a problem such as a sudden occurrence of a giant dust is caused.
本発明の目的は、 バリア膜としての特性や品質に優れる T i— A 1— N膜を再現性よく形成することを可能にしたスパッ夕夕ーゲッ トを提供 することにある。 より具体的には、 T i一 A 1— N膜を再現性よくェピ タキシャル成長させることを可能にしたスパヅ夕ターゲッ ト、 またダス 卜の発生を抑制することを可能にしたスパッ夕夕一ゲッ トを提供するこ とを目的としている。 さらに、 そのようなスパッ夕ターゲッ トを用いる ことによって、 特性、 品質、 製造歩留りなどを向上させたバリア膜およ ぴ電子部品を提供することを目的としている。 発明の開示  SUMMARY OF THE INVENTION An object of the present invention is to provide a sputter target capable of forming a Ti—A 1—N film having excellent characteristics and quality as a barrier film with good reproducibility. More specifically, a sputtering target that enables epitaxial growth of the Ti1-A1-N film with good reproducibility, and a sputtering target that enables suppression of dust generation. The purpose is to provide a get. It is another object of the present invention to provide a barrier film and an electronic component having improved characteristics, quality, manufacturing yield, and the like by using such a sputtering target. Disclosure of the invention
本発明者等は上記した課題を解決するために、 T i一 A 1合金夕一 ゲッ ト中の A 1組成や結晶粒径などが T i一 A 1—N膜に及ぼす影響に ついて検討した結果、 まず T i— A 1合金中の A 1を T i中に固溶させ るか、 あるいは T iとの金属間化合物として存在させて、 均一な合金組 織 （夕ーゲヅ ト組織） を得ることによって、 T i一 A 1— N膜のェピ夕 キシャル成長性を高めることができると共に、 ダス トの発生も抑制する ことが可能であることを見出した。 In order to solve the above-mentioned problems, the present inventors examined the effects of the A1 composition and the crystal grain size of the Ti-A1 alloy on the Ti-A1-N film. As a result, a uniform alloy structure (even-gate structure) is obtained by first dissolving A 1 in the Ti—A 1 alloy in Ti or as an intermetallic compound with Ti. By the way, Ti i A 1—N film It has been found that it is possible to improve the axial growth and to suppress the generation of dust.
特に、 T i— A 1—N膜のェピタキシャル成長性については、 夕一 ゲッ ト全体としての A 1含有量のバラヅキを低減することによって、 ェ ピ夕キシャル成長性が大幅に向上することを見出した。 言い換えると、 A 1の偏析を低減することによって、 T i 一 A 1— N膜のェピ夕キシャ ル成長性が向上する。 一方、 ダス トの発生については、 ターゲッ ト全体 としての結晶粒径のバラツキを低減することによって、 ダストの発生が 大幅に減少することを見出した。  In particular, with regard to the epitaxial growth of the Ti—A 1—N film, it was found that reducing the variation in the A 1 content of the entire target significantly improved the epitaxial growth. I found it. In other words, reducing the segregation of A 1 improves the epitaxial growth of the Ti-A 1-N film. On the other hand, with regard to dust generation, it was found that dust generation was significantly reduced by reducing the variation in crystal grain size of the target as a whole.
本発明はこのような知見に基づいてなされたものである。 本発明の第 1のスパヅ夕夕一ゲヅ トは、 T i— A 1合金により構成されたスパヅ夕 夕ーゲヅ トであって、 前記 T i - A 1合金中の A 1は、 T i中に固溶し た状態、 および T iと金属間化合物を形成した状態の少なくとも一方の 状態で存在しており、 かつ夕一ゲッ ト全体としての A 1含有量のバラヅ キが 10%以内であることを特徴としている。  The present invention has been made based on such findings. The first spa and evening gate of the present invention is a spa and evening gate made of Ti—A1 alloy, wherein A 1 in the Ti—A1 alloy is At least one of a solid solution state and a state in which Ti and an intermetallic compound are formed, and the variation of the A1 content of the entire getter is within 10%. It is characterized by:
本発明の第 2のスパッ夕夕一ゲッ トは、 T i— A 1合金により構成さ れたスパヅ夕夕一ゲヅ トであって、 前記 T i— A 1合金中の A 1は、 T i中に固溶した状態、 および T iと金属間化合物を形成した状態の少な く とも一方の状態で存在しており、 かつ前記 T i 一 A 1合金の平均結晶 粒径が 500 / m 以下であると共に、 ターゲッ ト全体としての結晶粒径の バラツキが 30%以内であることを特徴としている。  A second sputter-and-gatherer according to the present invention is a spa gutter composed of a Ti—A1 alloy, wherein A 1 in the Ti—A1 alloy is exists in at least one of a solid solution state and a state in which an intermetallic compound is formed with Ti, and the average crystal grain size of the Ti-A1 alloy is 500 / m or less. In addition, the variation in the crystal grain size of the target as a whole is within 30%.
本発明のスパヅ夕夕一ゲヅ トにおいて、 T i— A 1合金は A 1を 1~ 30原子％の範囲で含有することが好ましい。  In the spa bath of the present invention, the Ti—A1 alloy preferably contains A1 in the range of 1 to 30 atomic%.
本発明のバリア膜は、 上記した本発明のスパッ夕夕一ゲツ トを用いて 成膜してなる T i 一 A 1—N膜を具備することを特徴としている。 本発 明のバリァ膜は半導体基板に対するバリァ材として好適に用いられる。 本発明の電子部品は、 上記した本発明のバリァ膜を具備することを特 徴としている。 本発明の電子部品の具体的な形態としては、 半導体基板 と、 半導体基板上に形成されたバリア膜と、 バリア膜上に形成された薄 膜キャパシ夕とを具備する半導体メモリなどが挙げられる。 図面の簡単な説明 The barrier film of the present invention is characterized in that it comprises a Ti-A1-N film formed by using the above-described sputtering target of the present invention. The barrier film of the present invention is suitably used as a barrier material for a semiconductor substrate. An electronic component of the present invention is characterized by including the above-described barrier film of the present invention. Specific examples of the electronic component of the present invention include a semiconductor memory including a semiconductor substrate, a barrier film formed on the semiconductor substrate, and a thin film capacitor formed on the barrier film. BRIEF DESCRIPTION OF THE FIGURES
図 1は本発明の一実施形態による電子部品の概略構造を示す断面図で おる。 発明を実施するための形態  FIG. 1 is a sectional view showing a schematic structure of an electronic component according to one embodiment of the present invention. BEST MODE FOR CARRYING OUT THE INVENTION
以下、 本発明を実施するための形態について説明する。  Hereinafter, embodiments for carrying out the present invention will be described.
本発明のスパッ夕夕一ゲッ トは T i 一 A 1合金からなり、 例えば T i — A 1— N膜の形成に用いられるものである。 T i— A 1合金中の A 1 は、 T i中に固溶させるか、 あるいは T iとの金属間化合物として存在 させたものである。 T iと A 1との金属間化合物としては、 T i A l、 T i A l 3 s T i A l 2、 T i 3A 1などが挙げられる。 The sputtering target of the present invention is made of a Ti-A1 alloy, and is used, for example, for forming a Ti-A1-N film. A 1 in the Ti—A 1 alloy is a solid solution in Ti or an intermetallic compound with Ti. The intermetallic compound of T i and A 1, T i A l, T i A l 3 s T i A l 2, etc. T i 3 A 1 and the like.
このように、 A 1を固溶相や金属間化合物相として存在させることに よって、 均一な合金組織を得ることができる。 すなわち、 スパッ夕夕一 ゲッ トの組織を、 均一な T iと A 1の固溶体組織、 均一な T iと A 1の 金属間化合物組織、 あるいは均一な固溶体と金属間化合物との混合組織 とすることができる。 これらの均一な夕一ゲッ ト組織を得ることによつ て、 T i 一 A 1—N膜のェピタキシャル成長性が向上する。  Thus, a uniform alloy structure can be obtained by causing A1 to exist as a solid solution phase or an intermetallic compound phase. In other words, the structure of the target is a uniform solid solution structure of Ti and A1, an intermetallic compound structure of uniform Ti and A1, or a mixed structure of a uniform solid solution and intermetallic compound. be able to. By obtaining these uniform evening structures, the epitaxial growth of the Ti-A1-N film is improved.
これに対して、 T i— A 1合金 （スパヅ夕ターゲッ ト） 中に A 1が単 相として析出したり、 また A 1の偏祈が生じていたりすると、 ェピタキ シャル成長を妨げることになる。 A 1は固溶限までは T i中に固溶し、 それを超えた分は T iとの金属間化合物として存在するが、 A 1組成や 製造方法によっては A 1の偏析が生じるおそれが大きい。 本発明では A 1の析出や偏析を防止している。 On the other hand, if A 1 precipitates as a single phase in the Ti—A 1 alloy (spa target), or if A 1 is unbalanced, it will hinder epitaxial growth. A 1 forms a solid solution in Ti up to the solid solubility limit, and the excess exceeds it as an intermetallic compound with Ti. Depending on the production method, segregation of A1 is likely to occur. In the present invention, precipitation and segregation of A1 are prevented.
ここで、 T i— A 1合金夕一ゲッ ト中の A 1が固溶相または金属間化 合物相として存在することは、 X線回折により確認することができる。 すなわち、 T i— A 1合金ターゲッ トの任意の位置から試験片を採取し た後、 表面を # 1000 まで研磨し、 さらにパフ研磨する。 このような試 験片の X線回折パターンにおいて、 実質的に T iのピークと T i— A 1 金属間化合物 （ T i A l、 T i A l3、 T i A l2 など） のピークのみ であればよい。 言い換えると、 A 1のピークが実質的に現れなければ、 A 1は固溶相および金属間化合物相の少なく とも一方として存在してい ることが確認される。 Here, it can be confirmed by X-ray diffraction that A 1 in the Ti—A 1 alloy is obtained as a solid solution phase or an intermetallic compound phase. That is, after collecting a test piece from an arbitrary position of the Ti—A1 alloy target, the surface is polished to # 1000 and further puffed. In X-ray diffraction pattern of such a test piece, the peak of substantially T i peak and T i-A 1 intermetallic compound (T i A l, T i A l 3, T i A l 2 , etc.) It only needs to be. In other words, if the peak of A1 does not substantially appear, it is confirmed that A1 exists as at least one of the solid solution phase and the intermetallic compound phase.
なお、 X線回折パ夕一ンにおける有効ピークは最大強度ピークの 1/20 以上の強度比を有するものとする。 X線回折の測定条件は、 X 線： Cu, K—ひ 1、 電圧 ： 50kV、 電流： 100mA、 縦型ゴニオメ一夕、 発 散スリッ ト ： ldeg、 散乱スリッ ト ： ldeg、 受光スリ ヅ ト ： 0.15mm、 走査 モー ド ： 連続、 スキャ ンスピー ド ： 5° /min、 スキャ ンステップ ： 0.05° である。  The effective peak in the X-ray diffraction pattern shall have an intensity ratio of 1/20 or more of the maximum intensity peak. The measurement conditions of X-ray diffraction are as follows: X-ray: Cu, K—H1, voltage: 50 kV, current: 100 mA, vertical goniometer, divergent slit: ldeg, scattered slit: ldeg, light-receiving slit: 0.15mm, scan mode: continuous, scan speed: 5 ° / min, scan step: 0.05 °.
本発明のスパッ夕ターゲッ トを構成する T i— A 1合金は、 A 1を 1 〜 30 原子％の範囲で含有することが好ましい。 T i一 A 1合金夕一 ゲッ ト中の A 1量が 30 原子％を超えると、 本来 T i中に固溶する、 も しくは T iと金属間化合物を形成するはずの A 1が単相として析出する おそれが大きくなる。 すなわち、 A 1の偏析が生じやすくなる。 A 1が 単相として析出すると、 T i— A 1合金夕一ゲヅ トを用いて T i— A 1 — N膜などをスパヅ夕成膜した際に、 そのェピ夕キシャル成長性が低下 する。 さらに、 T i一 A 1— N膜の抵抗率なども増加し、 バリア膜とし ての特性低下を招くことになる。 T i— A 1合金夕一ゲッ ト中の A l量を 30 原子％以下とすること で、 夕一ゲヅ ト組織を均一な T iと A 1との固溶体組織、 均一な T iと A 1との金属間化合物組織、 あるいは均一な固溶体と金属間化合物との 混合組織とするができる。 このような均一な夕一ゲッ ト組織とすること によって、 得られる T i—A l— N膜の膜組織についても、 均一な T i Nと A 1との固溶体組織、 もしくは T i Nと A l Nとの固溶体組織とす るができる。 The Ti—A1 alloy constituting the sputtering target of the present invention preferably contains A1 in the range of 1 to 30 atomic%. When the amount of A 1 in the target exceeds 30 atomic%, the A 1 that originally forms a solid solution in Ti or forms an intermetallic compound with Ti is simply formed. The risk of precipitation as a phase increases. In other words, segregation of A 1 is likely to occur. When A 1 is precipitated as a single phase, the epitaxial growth of the Ti—A 1 —N film is reduced when a Ti—A 1 —N film or the like is formed using a Ti—A 1 alloy alloy gate. I do. Further, the resistivity of the Ti-A1-N film also increases, which causes a deterioration in characteristics as a barrier film. By reducing the amount of Al in the Ti—A1 alloy evening target to 30 atomic% or less, the evening gate structure can be made a uniform solid solution structure of Ti and A1, and a uniform Ti and A 1 or a mixed structure of a uniform solid solution and an intermetallic compound. With such a uniform evening-gated structure, the obtained Ti—A1—N film can have a uniform solid solution structure of TiN and A1 or a solid solution structure of TiN and A1. l It can be a solid solution structure with N.
一方、 T i一 A 1合金夕一ゲッ ト中の A 1量が 1 原子％未満である と、 本来の耐酸化性の向上効果を十分に得ることができない。 例えば、 A 1組成が 1原子％未満の T i— A 1合金夕一ゲッ トを用いて形成した T i—A l— N膜は酸化が進行しやすく、 その上に形成した膜との付着 力が低下して剥がれなどが生じやすくなる。 例えば、 T i一 A 1— N膜 と薄膜キャパシ夕の下部電極との付着力が低下する。  On the other hand, if the amount of A 1 in the Ti-A 1 alloy is less than 1 atomic%, the original effect of improving the oxidation resistance cannot be sufficiently obtained. For example, a Ti—A1—N film formed using a Ti—A1 alloy alloy having an A1 composition of less than 1 atomic percent tends to oxidize and adheres to a film formed thereon. The force is reduced and peeling is liable to occur. For example, the adhesive force between the Ti-A1-N film and the lower electrode of the thin film capacity is reduced.
さらに、 T i— A l— N膜中の A 1は膜自体の耐酸化性を高めるだけ でなく、 酸素のトラヅプ材としても機能する。 例えば、 T i— A 1— N 膜上に S R◦などの導電性酸化物からなる電極膜を形成した場合、 この 導電性酸化物中の酸素が半導体基板などの成膜基板中に拡散することが 抑制される。 このような点からも、 T i一 A 1合金ターゲッ ト中の A 1 量は 1原子％以上とすることが好ましい。  Furthermore, A 1 in the Ti—Al—N film not only increases the oxidation resistance of the film itself, but also functions as a trapping material for oxygen. For example, when an electrode film made of a conductive oxide such as SR◦ is formed on a Ti—A 1—N film, oxygen in the conductive oxide diffuses into a film formation substrate such as a semiconductor substrate. Is suppressed. From such a point, it is preferable that the amount of A 1 in the Ti-A 1 alloy target is 1 atomic% or more.
本発明のスパッ夕夕一ゲッ トを構成する T i— A 1合金の A 1含有量 (A l組成） は、 バリア膜自体の酸化をより良好に抑制し、 かつ得られ る膜のェピタキシャル成長性を一層高める上で、 1〜20 原子.％の範囲と することがより好ましい。 さらに、 A 1組成は 5〜15原子％の範囲とす ることが望ましい。  The A 1 content (Al composition) of the Ti—A 1 alloy that constitutes the sputtering target of the present invention suppresses the oxidation of the barrier film itself more favorably, and furthermore, the epitaxy of the obtained film. In order to further enhance the growth property, the content is more preferably in the range of 1 to 20 atom.%. Further, it is desirable that the A1 composition be in the range of 5 to 15 atomic%.
さらに、 本発明のスパッ夕ターゲッ トにおいては、 T i中に固溶させ るか、 あるいは T iとの金属間化合物とした存在させた A 1含有量の 夕一ゲヅ ト全体としてのバラヅキを 10 %以内としている。 ターゲッ ト 全体の A 1含有量のバラヅキを低く抑えることによって、 平滑なェピ夕 キシャル成長膜を再現性よく得ることが可能となる。 A 1含有量のバラ ヅキが 10 %を超えると、 得られる膜の A 1組成が部分的に異なること から、 例えば T i— A 1—Nの結晶成長性に差が生じ、 膜全体としての ェピタキシャル成長性が低下することになる。 夕一ゲヅ ト全体の A 1含 有量のバラヅキは 5 %以内とすることがより好ましく、 さらに好ましく は 1 %以内である。 Furthermore, in the sputtering target of the present invention, the A1 content of the solid solution in Ti or the existence of an intermetallic compound with Ti was determined. The variation in the evening gate as a whole is within 10%. By keeping the variation of the A1 content of the entire target low, a smooth epitaxial growth film can be obtained with good reproducibility. If the variation in the A1 content exceeds 10%, the resulting film has a partially different A1 composition, and thus, for example, a difference occurs in the crystal growth properties of Ti—A1—N, and Epitaxial growth will be reduced. The variation in the A1 content of the entire evening gate is more preferably 5% or less, and further preferably 1% or less.
ここで、 夕一ゲヅ ト全体としての A 1含有量のバラツキは、 以下のよ うにして求めた値を指すものとする。 すなわち、 ターゲッ トが円盤状の 場合、 ターゲッ トの中心部と、 中心部を通り円周を均等に分割した 2本 の直線上の外周から 10%の各位置 （中心部を入れて合計 5 箇所） から それそれ試験片を採取し、 これら 5点の試験片の A 1含有量をそれそれ 10回測定し、 この 10回の測定値の平均値を各試験片の A 1含有量とす る。 そして、 これらの測定値の最大値および最小値から、 { (最大値一 最小値） / (最大値 +最小値） } X 100 の式に基づいて、 本発明で規定 するバラヅキ [ % ] を求めるものとする。 A 1含有量は通常使用されて いる誘電結合プラズマ発光分光法により測定した値とする。  Here, the variation in the A1 content of the entire evening gate indicates a value obtained as follows. In other words, if the target is disk-shaped, each position is 10% from the center of the target and the outer circumference of two straight lines that pass through the center and divide the circumference evenly (total of 5 points including the center) Samples were taken from each sample, and the A1 content of these five test pieces was measured ten times, and the average of these ten measurements was taken as the A1 content of each test piece. . Then, from the maximum value and the minimum value of these measured values, a variation [%] specified in the present invention is calculated based on the formula of {(maximum value-minimum value) / (maximum value + minimum value)} × 100. Shall be. The A1 content is a value measured by a commonly used inductively coupled plasma emission spectroscopy.
本発明のスパッ夕夕一ゲッ トは、 高純度の T i— A 1合金で構成する ことが好ましい。 T i— A 1合金に含まれる不純物のうち、 特に酸素は 得られる T i— A l—N膜のェピタキシャル成長性を低下させるため、 T i - A 1合金の平均酸素含有量は 900ppm 以下とすることが好まし い。 さらに、 酸素は得られる T i— A 1—N膜の酸化を促進し、 その上 に形成される膜 （例えば薄膜キャパシ夕の下部電極） の付着力を低下さ せる。 このような点からも T i— A 1合金の平均酸素含有量は 900ppm 以下とすることが好ましい。 ただし、 T i— A 1合金夕一ゲッ トから完全に酸素を除去してしまう と、 得られる T i一 A 1—N膜のバリァ性が低下するおそれがあること から、 微量の酸素を含んでいることが好ましい。 具体的には、 T i一 A 1合金夕一ゲッ トは 10〜500ppm の範囲の酸素を含むことが好ましい。 より好ましい酸素含有量は 50〜400ppm の範囲である。 このような量の 酸素は T i - A 1一 N膜のバリァ性に対して有効に機能する。 It is preferable that the sputtering target of the present invention is made of a high-purity Ti—A1 alloy. Among the impurities contained in the Ti-A1 alloy, oxygen is particularly present. The average oxygen content of the Ti-A1 alloy is 900 ppm or less in order to reduce the epitaxial growth of the obtained Ti-Al-N film. It is preferable that In addition, oxygen promotes the oxidation of the resulting Ti-A1-N film and reduces the adhesion of the film formed thereon (eg, the lower electrode of the thin film capacitor). From such a point, the average oxygen content of the Ti-A1 alloy is preferably 900 ppm or less. However, if oxygen is completely removed from the Ti—A1 alloy, the barrier properties of the resulting Ti—A1—N film may be reduced. Preferably. Specifically, the Ti-A1 alloy should preferably contain oxygen in the range of 10 to 500 ppm. A more preferred oxygen content is in the range of 50-400 ppm. Such an amount of oxygen effectively functions for the barrier property of the Ti-A1N film.
T i— A 1合金夕一ゲッ ト中の酸素含有量のバラヅキは、 夕一ゲッ ト 全体として 30 %以内とすることが好ましい。 ターゲッ ト全体の酸素含 有量のバラヅキを低く抑えることによって、 それを用いて形成した T i —A 1— N膜のェピタキシャル成長性や耐酸化性などを全体的に再現性 よく向上させることができる。 さらに、 得られる T i一 A 1— N膜のバ リア性を均質化することができる。 夕ーゲツ ト全体の酸素含有量のバラ ヅキは、 前述した A 1含有量のバラヅキと同様にして求めるものとす る。 酸素含有量は通常使用されている不活性ガス融解赤外線吸収法によ り測定した値とする。  It is preferable that the variation in the oxygen content in the Ti—A1 alloy evening get be within 30% as a whole. By suppressing the variation in the oxygen content of the entire target to a low level, it is possible to improve the overall epitaxial growth and oxidation resistance of the Ti—A 1—N film formed using the same with good reproducibility. Can be. Further, the barrier properties of the obtained Ti-A1-N film can be homogenized. The variation in the oxygen content of the entire evening target is to be determined in the same manner as the variation in the A1 content described above. The oxygen content shall be the value measured by the commonly used inert gas fusion infrared absorption method.
なお、 本発明のスパヅ夕夕一ゲヅ ト （ T i一 A 1合金夕一ゲヅ ト） 中 の酸素以外の不純物元素については、 一般的な高純度金属材のレベル程 度であれは多少含んでいてもよい。 ただし、 酸素と同様にェピ夕キシャ ル成長性の向上などを図る上で、 他の不純物元素量についても低減する ことが好ましい。  The impurity elements other than oxygen in the spa bath and gate (Ti-A1 alloy bath) of the present invention are slightly different from those of general high-purity metal materials. May be included. However, it is preferable to reduce the amount of other impurity elements in order to improve the epitaxial growth property as in the case of oxygen.
本発明のスパッ夕ターゲッ トにおいて、 T i一 A 1合金を構成してい る結晶粒の平均粒径 （平均結晶粒径） は 50θΛ£ΐπ 以下であることが好ま しい。 さらに、 夕ーゲッ ト全体としての結晶粒径のバラツキは 30 %以 内であることが好ましい。 T i一 A 1合金夕ーゲッ トを搆成する結晶粒 を比較的微細化し、 かつターゲッ ト全体としての結晶粒径のバラツキを 低減することによって、 ダス トの発生を抑制することができる。 夕ーゲッ トの結晶粒径とダス トとの関係は数多く報告されている。 通 常、 ダス トと呼ばれているものは、 スパッタリングにより飛散した粒子 がスパッ夕装置内に配置された防着板や夕ーゲッ トの非エロージョン領 域に付着し、 これらが剥離して生じるフレーク状ものや、 結晶粒間の ギャップに生じた電位差により異常放電が発生し、 これに基づいて生じ るスプラッシュと呼ばれる溶融粒子などである。 いずれにしても、 通常 は大きさが 0.2〜0. 3 /m程度のものを指している。 In the sputtering target of the present invention, the average grain size (average crystal grain size) of the crystal grains constituting the Ti-A1 alloy is preferably not more than 50θΛ £ ΐπ. Further, it is preferable that the variation of the crystal grain size of the whole evening target is within 30%. The generation of dust can be suppressed by making the crystal grains forming the Ti-A1 alloy alloy relatively fine and reducing the variation in the crystal grain size of the entire target. There have been many reports of the relationship between the grain size of the target and dust. What is usually called dust is a type of flakes generated when particles scattered by sputtering adhere to the non-erosion area of the protection plate or the sunset placed in the sputter device and are separated. Discharge occurs due to abnormal electric discharge caused by the potential difference generated in the gap between crystal grains, and molten particles called splash generated based on this. In any case, it usually indicates a size of about 0.2 to 0.3 / m.
しかし、 従来の T i— A 1合金夕一ゲッ トから突発的に発生するダス トは、 大きさが 1 m 以上とこれまでのダス トと比較して大きい。 ま た、 形状も岩石のような塊状である。 この塊状のダス トは、 結晶粒の一 部もしくは結晶粒自体がスパッ夕リングにより抽出されたようなモード になっている。 そして、 ターゲッ ト全体としての結晶粒径にバラヅキが 生じていると、 このような巨大なダス 卜の発生率が増大する。  However, the dust that is suddenly generated from the conventional Ti—A1 alloy one-gap is larger than 1 m, which is 1 m or more. The shape is also massive like rock. This massive dust has a mode in which a part of the crystal grains or the crystal grains themselves are extracted by sputtering. If the crystal grain size of the target as a whole varies, the incidence of such a huge dust increases.
これに対して、 T i一 A 1合金ターゲッ トの平均結晶粒径を 500 m 以下とすると共に、 ターゲッ ト全体と しての結晶粒径のバラヅキを 30%以内とすることによって、 熱応力などの影響による結晶粒の一部も しくは結晶粒自体の飛散を抑えることが可能となる。 その結果として、 巨大ダス トの発生が抑制され、 T i一 A 1—N膜の歩留りを大幅に向上 させることができる。  On the other hand, by setting the average crystal grain size of the Ti-A1 alloy target to 500 m or less and the variation of the crystal grain size of the entire target to 30% or less, thermal stress, etc. It is possible to suppress the scattering of a part of the crystal grains or the crystal grains themselves due to the influence of. As a result, generation of giant dust is suppressed, and the yield of the Ti-A1-N film can be significantly improved.
T i— A 1合金夕一ゲッ トの結晶粒径は 300 m 以下がより好まし く、 さらに好ましくは 200 zm 以下である。 また、 夕ーゲツ ト全体とし ての結晶粒径のバラツキは 15 %以内とすることがより好ましく、 さら に好ましくは 10 %以内である。 なお、 前述したように、 A 1を T i中 に固溶させた均一な固溶体組織や T iと A 1の均一な金属間化合物組織 も、 巨大ダス トの抑制に効果を及ぼしている。  The grain size of the Ti—A1 alloy is preferably 300 m or less, more preferably 200 zm or less. Further, the variation in the crystal grain size of the entire evening target is more preferably within 15%, and further preferably within 10%. As described above, a uniform solid solution structure in which A1 is dissolved in Ti and a uniform intermetallic compound structure of Ti and A1 also have an effect on suppression of giant dust.
ここで、 T i— A 1合金ターゲッ トの平均結晶粒径は、 以下のように して求めた値とする。 まず、 スパッタターゲッ トの表面から試験片を採 取し、 試験片の表面を HF ： HN03： H20=2:2:l のエッチング液で エッチングした後、 光学顕微鏡で組織 ϋ察を行う。 光学顕微鏡の測定視 野または写真上に面積が既知の円 （直径 79.8mm) を描き、 円内に完全 に含まれる結晶粒の個数 （個数 A) と、 円周により切断される結晶粒の 個数 （個数 B) とを数える。 測定倍率は円の中に完全に含まれる結晶粒 の個数が 30個以上となるように設定する。 結晶粒の個数 Bは 1/2に換 算して、 円内の結晶粒の総数 nは個数 A+個数 B/2 とする。 この円内 の結晶粒の総数 nと測定倍率 Mと円の面積 A (mm2) とから、Here, the average grain size of the Ti—A1 alloy target is as follows: And the value obtained. Firstly, was collected adopted a test piece from the surface of the sputter coater rodents DOO, the surface of the test piece HF: HN0 3: H 2 0 = 2: 2: after etching with an etching solution of l, performing tissue ϋ observation under an optical microscope . Draw a circle (diameter 79.8 mm) with a known area on the measurement field of the optical microscope or on the photograph, and the number of crystal grains completely included in the circle (number A) and the number of crystal grains cut by the circumference (Number B). The measurement magnification is set so that the number of crystal grains completely included in the circle is 30 or more. The number B of crystal grains is converted to 1/2, and the total number n of crystal grains in a circle is set to A + B / 2. From the total number n of crystal grains in this circle, the measurement magnification M, and the area A (mm2) of the circle,
Figure imgf000015_0001
Figure imgf000015_0001
の式に基づいて、 平均結晶粒径 d (mm) を算出する。 Calculate the average crystal grain size d (mm) based on the formula.
夕一ゲッ ト全体としての結晶粒径のバラヅキは、 夕一ゲッ 卜の中心部 と、 中心部を通り円周を均等に分割した 2本の直線上の各外周近傍位置 およびその 1/2の距離の各位置 （中心部を入れて合計 9箇所） からそれ それ試験片を採取し、 これら 9点の試験片それそれの平均結晶粒径を上 記した方法で 10回測定し、 この 10回の測定値の平均値を各試験片の結 晶粒径とする。 そして、 これらの測定値の最大値および最小値から、 { (最大値一最小値） / (最大値 +最小値） } X100 の式に基づいて、 本発明で規定する結晶粒径のバラヅキ [%] を求めるものとする。 な お、 試験片の形状は長さ 10mm、 幅 10mmとする。  The variation in the crystal grain size of the entire evening-get is the central part of the evening-get, the position near each outer circumference on two straight lines passing through the center and dividing the circumference equally, and 1/2 of that Test specimens were taken from each position at the distance (a total of 9 places including the center), and the average crystal grain size of these 9 test specimens was measured 10 times by the above method. The average value of the measured values shall be the crystal grain size of each test piece. Then, from the maximum value and the minimum value of these measured values, based on the formula of {(maximum value-minimum value) / (maximum value + minimum value)} X100, the variation of the crystal grain size defined by the present invention [% ]. The test piece shall be 10 mm long and 10 mm wide.
本発明のスパッ夕夕一ゲッ トの製造方法は、 特に限定されるものでは ないが、 以下に示すような溶解法を適用して作製することが好ましく、 さらには各溶解法の種々の条件を制御して A 1含有量のバラヅキを低減 させることが好ましい。  The manufacturing method of the sputter bath of the present invention is not particularly limited, but it is preferable to manufacture it by applying a dissolving method as described below. It is preferable to reduce the variation in the A1 content by controlling.
まず、 4N 程度の髙純度の T iおよび A 1を用意し、 これらをアーク 溶解法、 電子ビーム （EB) 溶解法、 コールドウォール溶解法などの方 法で溶解して、 T i一 A 1合金ィンゴッ トを作製する。 これら溶解法の うち、 特にコールドウォール溶解法を適用することが好ましい。 コール ドウオール溶解法によれば、 その溶解条件を制御することによって、 A 1の偏析を抑えて均一な合金組織を再現性よく得ることができる。 コー ルドウォール溶解法は、 不純物元素の減少およびそのバラツキの低減に 対しても効果を発揮する。 First, prepare Ti and A1 with a high purity of about 4N, and use them for arc melting, electron beam (EB) melting, cold wall melting, etc. The Ti-A1 alloy ingot is produced by melting. Among these dissolution methods, it is particularly preferable to apply the cold wall dissolution method. According to the cold wall melting method, by controlling the melting conditions, segregation of A1 can be suppressed and a uniform alloy structure can be obtained with good reproducibility. The cold wall melting method is also effective in reducing impurity elements and their variations.
コールドウオール溶解法を適用する際の具体的な条件としては、 まず 溶解開始前の圧力を 1X10一6 Pa程度 （1X10— 4〜ΐχΐο- 7Pa) とし、 溶解 前に脱ガス処理 （ベ一キング） を 2回程度実施する。 溶解開始時には圧 力を 1X10— 5Pa程度 （ 1 X 10—4〜 1 x io- 6pa) とし、 溶解中の圧力は IX 10— 4pa 程度 （1 X10— 3〜； lxl0-5pa) とする。 溶解開始時の電力は 5kW 程度とし、 溶解時の最大圧力は 230kW程度に設定する。 溶解時間は 40 分程度とすることが好ましい。 Specific conditions for the application of cold wall dissolution method, first dissolve before the start 1X10 one 6 Pa about the pressure (1X10- 4~ΐχΐο- 7 Pa) and then, dissolved before the degassing treatment (base one king ) Is performed about twice. Melt onset of about 1X10- 5 Pa the pressure at the time (1 X 10-4~ 1 x io- 6p a) and then, the pressure in the lysis IX 10- 4p a degree (1 X10- 3~; lxl0-5p a) And The electric power at the start of melting is about 5 kW, and the maximum pressure at the time of melting is set at about 230 kW. The dissolution time is preferably about 40 minutes.
さらに、 コールドウォール溶解を実施した後に、 A 1含有量のバラヅ キを低減するために、 T i一 A 1合金の融点の 80~90%の範囲の温度 で溶体化処理を行うことが好ましい。 溶体化処理は lxlO_lPa以下の真 空中または Ar雰囲気中で 24 時間以上実施することが好ましい。 この ような溶体化処理は A 1含有量のバラヅキの抑制に限らず、 酸素含有量 のバラツキの低減、 結晶粒径の微細化や平均化に対しても効果を示すも のである。  Further, after performing cold wall melting, it is preferable to perform a solution treatment at a temperature in the range of 80 to 90% of the melting point of the Ti-A1 alloy in order to reduce variation in the A1 content. The solution treatment is preferably performed for 24 hours or more in a vacuum of less than lxlO_lPa or in an Ar atmosphere. Such a solution treatment is effective not only in suppressing the variation in the A1 content but also in reducing the variation in the oxygen content, miniaturizing and averaging the crystal grain size.
ここで、 溶体化処理温度があまり高すぎると、 結晶粒の成長が急激に 起こるために割れが生じやすくなる。 一方、 溶体化処理温度があまり低 すぎると、 A 1の分散効果を十分に得ることができない。 このようなこ とから、 溶体化処理温度は T i - A 1合金の融点の 80〜90%の範囲の 温度とすることが好ましい。 より好ましい温度は融点の 85〜90%の範 囲である。 また、 溶体化処理時の真空度が不十分であると T i— A 1合 金が酸化しやすくなるため、 その際の圧力は 1 X 10一 lPa以下とする。 さ らに、 溶体化処理の時間があまり短いと A 1の分散効果が不十分となる ため、 その時間は 24時間以上とすることが好ましい。 Here, if the solution treatment temperature is too high, cracks are likely to occur due to rapid growth of crystal grains. On the other hand, if the solution treatment temperature is too low, the dispersion effect of A1 cannot be sufficiently obtained. For this reason, the solution treatment temperature is preferably set to a temperature in the range of 80 to 90% of the melting point of the Ti-A1 alloy. More preferred temperatures are in the range of 85-90% of the melting point. In addition, if the degree of vacuum during the solution treatment is insufficient, T i—A 1 Since gold is easily oxidized, the pressure at that time should be 1 X 10 1 lPa or less. Further, if the solution treatment time is too short, the dispersion effect of A1 becomes insufficient, so that the time is preferably at least 24 hours.
なお、 アーク溶解法や E B溶解法では、 A 1の偏祈が発生するおそれ が大きいため、 複数回 （例えば 2〜3 回） 溶解を実施することが好まし い。 このように、 アーク溶解や E B溶解を複数回実施することによつ て、 A 1の偏析を減少させることができる。  In the arc melting method and the EB melting method, it is preferable to perform the melting several times (for example, two to three times) because there is a high possibility that A1 may be biased. Thus, segregation of A1 can be reduced by performing arc melting and EB melting several times.
次に、 得られたインゴッ トに対して、 必要に応じて鍛造や圧延などの 塑性加工を施す。 この際の加工率は例えば 60〜95 %とする。 このよう な塑性加工によれば、 インゴッ トに適当量の熱エネルギーを与えること ができ、 そのエネルギーによって A 1や酸素の均質化を図ることができ る。 加工率があまり高いと、 加工時に割れが発生しやすくなる。 逆に、 加工率があまり低いと、 後工程での再結晶化が不十分となる。 このよう なことから、 塑性加工時の加工率は 60〜95 %の範囲とすることが好ま しい。 より好ましい加工率は 70〜90 %の範囲であり、 さらに好ましく は 80〜90 %の範囲である。  Next, the obtained ingot is subjected to plastic working such as forging or rolling as necessary. The processing rate at this time is, for example, 60 to 95%. According to such plastic working, an appropriate amount of thermal energy can be given to the ingot, and the energy can be used to homogenize A1 and oxygen. If the processing rate is too high, cracks are likely to occur during processing. Conversely, if the working ratio is too low, recrystallization in the subsequent steps will be insufficient. For this reason, it is preferable that the working ratio during plastic working be in the range of 60 to 95%. A more preferable processing rate is in the range of 70 to 90%, and further preferably, in the range of 80 to 90%.
この後、 丁 1ー八 1合金素材を 900〜1200°Cの温度でァニールして再 結晶化させる。 再結晶化の条件を調整することによって、 平均結晶粒径 やそのバラツキを本発明の範囲内に制御することができる。 ァニール温 度があまり高いと、 再結晶粒の粒径が大きくなりすぎる。 逆に、 ァニ一 ル温度があまり低いと、 再結晶化が不十分となる。 従って、 ァニール温 度は 900〜1200°Cの範囲とすることが好ましい。 より好ましいァニール 温度は 950〜1150°Cの範囲であり、 さらに好ましくは 1000~ 1100°Cの範 囲である。  Thereafter, the alloy material is annealed at a temperature of 900 to 1200 ° C and recrystallized. By adjusting the recrystallization conditions, the average crystal grain size and its variation can be controlled within the scope of the present invention. If the annealing temperature is too high, the size of the recrystallized grains becomes too large. Conversely, if the annealing temperature is too low, recrystallization will be insufficient. Therefore, the annealing temperature is preferably in the range of 900 to 1200 ° C. The preferred annealing temperature is in the range of 950 to 1150 ° C, and more preferably in the range of 1000 to 1100 ° C.
上述した溶解法により得られる T i一 A 1合金からなる夕ーゲッ ト素 材を所望の夕一ゲッ ト形状に機械加工し、 例えば A 1や C uからなる バヅキングプレートと接合することによって、 目的とするスパッ夕夕一 ゲヅ トが得られる。 バッキングプレートとの接合には拡散接合、 あるい は I n、 Z nおよび S nの少なく とも 1種、 あるいはそれらを含むろう 材を用いたろう付け接合などを採用することができる。 また、 別個の バッキングプレートを使用するのではなく、 スパッ夕夕一ゲッ トの作製 時にバッキングプレート形状を同時に形成した一体型のスパッ夕夕一 ゲッ 卜であってもよい。 The evening-get material consisting of the Ti-A1 alloy obtained by the above-mentioned melting method is machined into the desired evening-get shape and made of, for example, A1 or Cu. By joining with the backing plate, the desired sputter and evening gate can be obtained. Diffusion bonding, brazing bonding using at least one of In, Zn and Sn, or a brazing material containing them can be employed for bonding to the backing plate. Also, instead of using a separate backing plate, an integrated sputter plate that simultaneously forms the backing plate shape when the spatter plate is manufactured may be used.
本発明のバリァ膜は、 上述した本発明のスパヅ夕夕一ゲヅ ト （T i 一 A 1合金夕一ゲッ ト） を用いて、 例えば A rと N 2 の混合ガスによる化 相スパッ夕により成膜した T i— A l— N膜 （ T i i-xA 1 ΧΝ膜（0. 01 ≤χ≤0.3 ) ) を具備するものである。 このようにして得られる T i — A 1 一 N膜は、 S i基板などの半導体基板に対するェビタキシャル成長性 に優れ、 バリア膜として良好な特性を有すると共に、 ダス トの発生数も 大幅に低減されたものである。 本発明の T i— A 1合金夕ーゲッ トを用 いることによって、 特性および品質に優れるバリア膜 （T i— A l— N 膜） を歩留りよく得ることができる。 Baria film of the present invention uses Supadzu evening evening one gate Uz city of the present invention described above (T i one A 1 alloy evening one rodents g), for example, by A r and mixing by reduction phase sputtering evening gas N 2 those having a film-formed T i-a l-N film (T i i- x a 1 Χ Ν film (0. 01 ≤χ≤0.3)). The Ti—A1N film obtained in this way has excellent EB growth on semiconductor substrates such as Si substrates, has good properties as a barrier film, and greatly reduces the number of dusts generated. It is a thing. By using the Ti—A1 alloy target of the present invention, a barrier film (Ti—Al—N film) having excellent characteristics and quality can be obtained with good yield.
本発明の T i 一 A 1— N膜は、 例えば S rや B aなどをはじめとする 各種元素に対するバリア性に優れ、 かつ抵抗率が Ω ' cm以下とい うような低抵抗を有する。 従って、 このような T i— A 1— N膜を半導 体基板と各種素子とのバリア膜として用いることによって、 半導体基板 と素子構成層との間の相互拡散を良好に抑制することができる。 さら に、 高温ァニール （例えば 600°C以上） による T i— A 1— N膜の酸化 を防ぐことができるため、 T i— A 1—N膜と素子構成層との界面での 付着力の低下を抑制することが可能となる。 すなわち、 T i—A l—N 膜上の素子構成層の剥がれなどを抑制することができる。 さらに、 素子 構成層のェピタキシャル成長を阻害することがないため、 素子構成層の 特性向上を図ることができる。 The Ti-A1-N film of the present invention has an excellent barrier property against various elements such as Sr and Ba, and has a low resistance such as a resistivity of Ω'cm or less. Therefore, by using such a Ti—A 1—N film as a barrier film between the semiconductor substrate and various elements, the mutual diffusion between the semiconductor substrate and the element constituent layer can be favorably suppressed. . Furthermore, since oxidation of the Ti—A 1—N film due to high-temperature annealing (for example, at 600 ° C. or higher) can be prevented, the adhesive force at the interface between the Ti—A 1—N film and the element constituent layer can be reduced. It is possible to suppress the decrease. That is, it is possible to suppress peeling of the element constituent layer on the Ti-Al-N film. Furthermore, since the epitaxial growth of the element configuration layer is not hindered, The characteristics can be improved.
上述した T i一 A l— N膜は、 半導体基板に対するバリア材として好 適である。 このような本発明のバリア膜は、 各種の電子部品に使用する ことができる。 具体的には、 スィッチ用トランジスタを形成した半導体 基板と、 ぺロブスカイ ト型酸化物からなる誘電体薄膜を用いた薄膜キヤ パシ夕 （メモリセル） とを組合せた、 F RAMや D RAMなどの半導体 メモリに対して、 本発明のバリァ膜は効果的に使用される。  The Ti-Al-N film described above is suitable as a barrier material for a semiconductor substrate. Such a barrier film of the present invention can be used for various electronic components. Specifically, semiconductors such as FRAMs and DRAMs, which combine a semiconductor substrate on which a switch transistor is formed and a thin film capacitor (memory cell) using a dielectric thin film made of perovskite oxide For memories, the barrier film of the present invention is effectively used.
図 1は本発明の電子部品の一実施形態としての半導体メモリのキャパ シ夕部分を模式的に示す断面図である。 同図において、 1は図示を省略 したスィッチ用トランジスタが形成された半導体基板 （ S i基板） であ る。 この半導体基板 1上にはバリア膜 2 として、 上述した本発明の T i — A l — N膜 （ T i ΐ-χΑ 1 ΧΝ膜（0.01≤ <0.3)) が形成されてお り、 さらにその上に薄膜キャパシ夕 3が形成されている。 FIG. 1 is a sectional view schematically showing a capacity portion of a semiconductor memory as one embodiment of an electronic component of the present invention. In FIG. 1, reference numeral 1 denotes a semiconductor substrate (Si substrate) on which a switching transistor (not shown) is formed. On the semiconductor substrate 1, the above-described Ti—Al—N film (T i i-χΑ 1 Χ Ν film (0.01≤ <0.3)) of the present invention is formed as a barrier film 2. A thin film capacitor 3 is formed on top of it.
薄膜キャパシ夕 3は、 バリア膜 2上に順に形成された、 下部電極 4、 誘電体薄膜 5および上部電極 6を有している。 下部電極 4には、 P t、 Au、 P d、 I r、 R h、 R Θ、 R uなどの貴金属、 およびそれらの合 金 （P t — R hや P t — R uなど） 、 あるいは S r R u 03、 C a R u 03ヽ B a R u 03 およびこれらの固溶系 （例えば （B a， S r ) R 〇3 や （ S r , C a) R u 03) などの導電性べロブスカイ ト型酸化物 などが使用される。 上部電極 6の構成材料は特に限定されるものではな いが、 下部電極 4と同様な貴金属 （合金を含む） や導電性ぺロブスカイ ト型酸化物などを使用することが好ましい。 The thin film capacitor 3 has a lower electrode 4, a dielectric thin film 5, and an upper electrode 6 formed on the barrier film 2 in order. The lower electrode 4 includes noble metals such as Pt, Au, Pd, Ir, Rh, RΘ, and Ru, and alloys thereof (such as Pt—Rh and Pt—Ru), or S r R u 0 3, C a R u 0 3ヽB a R u 0 3 and their solid solution system (e.g. (B a, S r) R 〇 3 and (S r, C a) R u 0 3) For example, a conductive perovskite oxide such as is used. The constituent material of the upper electrode 6 is not particularly limited, but it is preferable to use a noble metal (including an alloy) or a conductive perovskite oxide similar to the lower electrode 4.
誘電体薄膜 5 としては、 ベロブスカイ ト型結晶構造を有する誘電体材 料が好適である。 このような誘電体材料としては、 AB 03 で表される ぺロプスカイ ト型酸化物が挙げられる。 特に、 チタン酸バリウム （B a T i 03 (B T 0 ) ) を主成分とし、 その Aサイ ト元素 （B a ) の一部 を S rや C aなどの元素で置換したり、 また Bサイ 卜元素 （ T i ) の一 部を Z r、 H f 、 S nなどの元素で置換したぺロプスカイ ト型酸化物 (B S TOなど） が好ましく用いられる。 As the dielectric thin film 5, a dielectric material having a bevelskite-type crystal structure is preferable. An example of such a dielectric material is a perovskite oxide represented by AB03. Particularly, barium titanate (B a T i 0 3 ( BT 0)) was used as a main component, a part of the A site elements (B a) Is replaced by an element such as Sr or Ca, or a perovskite oxide (BSTO) in which part of the B-site element (T i) is replaced by an element such as Zr, Hf, or Sn. Are preferably used.
B TOを主成分とするベロブスカイ ト型酸化物は、 Bサイ ト元素や A サイ ト元素の置換量、 さらには格子歪に基づく歪量によって、 強誘電体 もしくは常誘電体となる。 従って、 ぺロブスカイ ト型酸化物の組成や歪 量を適宜設定することによって、 薄膜キャパシ夕 3の使用目的に応じた 誘電体薄膜 5を得ることができる。 例えば、 B aaS r i-aT i 03 ( BBerovskite-type oxides mainly composed of BTO become ferroelectric or paraelectric depending on the amount of substitution of the B-site element and the A-site element and the amount of strain based on lattice strain. Therefore, by appropriately setting the composition and the amount of strain of the perovskite oxide, the dielectric thin film 5 corresponding to the intended use of the thin film capacitor 3 can be obtained. For example, B a a S r i- a T i 03 (B
S TO) の場合、 B aのモル分率 aが 0.3〜1 の範囲であると強誘電性 を示す。 一方、 B aのモル分率 aが 0〜0.3 の範囲であると常誘電性を 示す。 これらは Bサイ ト元素の置換量によっても変化する。 In the case of (STO), ferroelectricity is exhibited when the molar fraction a of Ba is in the range of 0.3 to 1. On the other hand, when the molar fraction a of Ba is in the range of 0 to 0.3, it exhibits paraelectricity. These also change depending on the substitution amount of the B site element.
なお、 誘電体薄膜 5には B T0や B S T 0以外のベロブスカイ ト型酸 化物、 例えば S r T i〇3、 C a T i〇3、 B a S n03、 B a Z r 03 などの単純べロプスカイ ト型酸化物、 B a (M i/3Nb2/3) ◦ 3、 B a (Mgi/3T a2/3) 03 などの複合べロプスカイ ト型酸化物、 および これらの固溶系などを適用することも可能である。 ぺロプスカイ ト型酸 化物の組成については、 化学量論比からの多少のずれは許容されること は言うまでもない。 Incidentally, Berobusukai preparative oxides other than B T0 and BST 0 is the dielectric thin film 5, for example, S r T I_rei_3, C a T I_rei_3, simple, such as B a S n0 3, B a Z r 03 base Ropusukai preparative oxide, B a (M i / 3 Nb 2/3) ◦ 3, B a (Mgi / 3 T a 2/3) 0 3 composite base Ropusukai preparative oxides such as, and these solid It is also possible to apply a solution system or the like. It goes without saying that a slight deviation from the stoichiometric ratio is permissible for the composition of the perovskite oxide.
このような半導体メモリにおいては、 バリァ特性および耐酸化性に優 れる T i一 A 1— N膜からなるバリア膜 2によって、 半導体基板 1上に その特性を低下させることなく薄膜キャパシ夕 3を良好に形成すること が可能となる。 特に、 薄膜キャパシ夕 3の下部電極 4とバリア膜 2との 間の剥離などを良好に抑制することができる。 バリア層 2の膜厚は、 拡 散防止効果が得られる範囲内で薄い方がよく、 具体的には 10〜50mn の 範囲とすることが好ましい。  In such a semiconductor memory, the thin film capacity 3 can be improved on the semiconductor substrate 1 without deteriorating its characteristics by the barrier film 2 composed of a Ti-A1-N film having excellent barrier characteristics and oxidation resistance. It becomes possible to form it. In particular, peeling between the lower electrode 4 of the thin film capacitor 3 and the barrier film 2 can be favorably suppressed. The thickness of the barrier layer 2 is preferably as thin as possible within a range in which the effect of preventing diffusion can be obtained, and specifically, is preferably in the range of 10 to 50 mn.
さらに、 ノ リア膜 2としての T i— A 1— N膜はェビタキシャル成長 膜であり、 その上の下部電極 4および誘電体薄膜 5のェピタキシャル成 長を促進するため、 例えばェピ夕キシャル成長時に導入される歪により 誘起された強誘電特性や高誘電特性を利用した薄膜キャパシ夕を、 半導 体基板 1上に良好な膜質で作製することが可能となる。 従って、 このよ うな薄膜キャパシ夕とトランジス夕とを半導体基板上に高度に集積する ことによって、 実用性が高くかつ信頼性の高い F R A Mや D R A Mなど の半導体メモリを高歩留りで作製することができる。 Furthermore, the Ti—A 1—N film as the Noria film 2 is grown by epitaxial growth. In order to promote the epitaxial growth of the lower electrode 4 and the dielectric thin film 5 thereon, for example, a ferroelectric property or a high dielectric property induced by strain introduced during epitaxial growth is used. It is possible to produce a thin film capacitor on the semiconductor substrate 1 with good film quality. Therefore, by highly integrating such a thin film capacity and a transistor on a semiconductor substrate, highly practical and highly reliable semiconductor memories such as FRAM and DRAM can be manufactured with high yield.
次に、 本発明の具体的な実施例について説明する。  Next, specific examples of the present invention will be described.
実施例 1 Example 1
高純度の T i片と A 1片をコ一ルドウォール溶解法で溶解して、 表 1 に示す A 1含有量を有する各合金インゴッ ト （直径 105mm) をそれそれ 作製した。 コ一ルドウォール溶解工程は、 まず溶解開始前の圧力を I X 10~6pa とし、 溶解前に脱ガス処理 （ベーキング） を 2 回実施した。 溶 解開始時に圧力を l x l0—5paに調整し、 溶解中の圧力は 1 X 10— 4pa とし た。 溶解開始時の電力は 5kWとし、 溶解時の最大圧力は 230kWとした。 溶解時間は 40 分に設定した。 このようなコールドウオール溶解により 得られた各合金ィンゴッ トに、 表 1に示す温度と時間で溶体化処理を施 した。 High purity Ti pieces and A1 pieces were melted by a cold wall melting method, and each alloy ingot (diameter: 105 mm) having the A1 content shown in Table 1 was produced. Koh one field wall dissolution step, first the pressure before melt onset and IX 10 ~ 6p a, was degassed before dissolving (baking) was performed twice. The pressure was adjusted to lx l0-5p a at dissolve the start, the pressure in the dissolution was 1 X 10- 4p a. The electric power at the start of melting was 5 kW, and the maximum pressure at melting was 230 kW. The dissolution time was set at 40 minutes. Each alloy ingot obtained by such cold wall melting was subjected to a solution treatment at the temperature and time shown in Table 1.
次に、 上記した各合金ィ ンゴッ トに対して、 表 1 に示す加工率で 1000°Cにて熱間圧延を施した後、 900°Cで 1 時間ァニールして再結晶化 させた。 再結晶化後の各合金素材を研削、 研磨した後、 A 1製バッキン グプレートとホヅ トプレスにより拡散接合し、 さらに機械加工を施すこ とによって、 直径 320mm x厚さ 10腿 の T i— A 1合金夕ーゲヅ トをそ れそれ作製した。  Next, each of the above-mentioned alloy ingots was subjected to hot rolling at a working rate shown in Table 1 at 1000 ° C and then reannealed at 900 ° C for 1 hour. After grinding and polishing each alloy material after recrystallization, it is diffusion bonded by A1 backing plate and hot press, and further machined to obtain a Ti—A1 with a diameter of 320 mm and a thickness of 10 thighs. Alloy evening gates were made individually.
このようにして得た各 T i— A 1合金夕一ゲヅ トの X線回折を実施し たところ、 いずれの X線回折パターンにも T iピークと T i一 A 1金属 間化合物のピークしか出現していないことを確認した。 すなわち、 各 i一 A 1合金夕ーゲッ トは、 T i— A 1固溶体と T i— A 1金属間化合 物組織とからなる均一な組織を有していた。 さらに、 これら各 T i _A 1合金ターゲッ トの A 1含有量のバラヅキ、 平均酸素含有量、 酸素含有 量のバラツキを、 前述した方法にしたがってそれそれ測定した。 これら の測定結果を表 1に示す。 The X-ray diffraction of each Ti-A1 alloy obtained in this manner was performed. The X-ray diffraction pattern showed that the Ti peak and the Ti-A1 metal It was confirmed that only the peak of the inter-compound appeared. That is, each i-A1 alloy alloy had a uniform structure consisting of a Ti-A1 solid solution and a Ti-A1 intermetallic compound structure. Further, the variation in the A1 content, the average oxygen content, and the variation in the oxygen content of each of these Ti_A1 alloy targets were measured in accordance with the above-described methods. Table 1 shows the measurement results.
Figure imgf000022_0001
Figure imgf000022_0001
* ： T i - A 1合金の融点に対する比率 実施例 2  *: Ratio to melting point of Ti-A1 alloy Example 2
高純度の T iと A 1片をアーク溶解法で溶解して、 表 2に示す A 1含 有量を有する各合金ィ ンゴッ ト （直径 105mm) をそれそれ作製した。 アーク溶解は、 まず 6.65x10— 3pa まで真空引きし、 Arを 1.9xlo4pa まで導入した後、 出力 150kWで実施した。 アーク溶解の回数はそれそれ 表 2に示した通りである。 次いで、 アーク溶解により得られた各合金ィ ンゴッ トに対して、 表 2に示す温度で 30 時間の溶体化処理を施した。 これらの合金素材に 1000°Cで熱間圧延を施した後、 実施例 1と同様に して、 直径 320mm x厚さ 10mm の T i— A 1合金夕一ゲヅ トをそれそれ 作製した。 High-purity Ti and A1 pieces were melted by the arc melting method, and each alloy ingot (105 mm in diameter) having the A1 content shown in Table 2 was produced. Arc melting is evacuated to First 6.65x10- 3p a, after the introduction of the Ar to 1.9Xlo4p a, was carried out at output 150 kW. The number of arc melting times is as shown in Table 2. Next, each alloy ingot obtained by arc melting was subjected to a solution treatment at a temperature shown in Table 2 for 30 hours. After subjecting these alloy materials to hot rolling at 1000 ° C, the same as in Example 1 was performed. Then, a Ti—A1 alloy evening gate having a diameter of 320 mm and a thickness of 10 mm was manufactured in each case.
このようにして得た各 T i— A 1合金夕ーゲッ トの X線回折を実施し たところ、 いずれの X線回折パターンにも T iピークと T i— A 1金属 間化合物のピークしか出現していないことを確認した。 すなわち、 各 T i一 A 1合金夕ーゲッ トは、 T i— A 1固溶体と T i— A 1金属間化合 物組織とからなる均一な組織を有していた。 さらに、 これら各 T i— A 1合金ターゲッ トの A 1含有量のバラヅキ、 平均酸素含有量、 酸素含有 量のバラヅキを、 前述した方法にしたがってそれぞれ測定した。 これら の測定結果を表 2に示す。 表 2  X-ray diffraction of each Ti—A1 alloy obtained in this manner was performed. In each X-ray diffraction pattern, only the Ti peak and the peak of the Ti—A1 intermetallic compound appeared. Not sure that. That is, each Ti-A1 alloy target had a uniform structure consisting of a Ti-A1 solid solution and a Ti-A1 intermetallic compound structure. Further, the variation in the A1 content, the average oxygen content, and the variation in the oxygen content of each of these Ti—A1 alloy targets were measured in accordance with the above-described methods. Table 2 shows the measurement results. Table 2
Figure imgf000023_0001
Figure imgf000023_0001
* ： T i - A 1合金の融点に対する比率 実施例 3  *: Ratio of melting point of Ti-A1 alloy Example 3
高純度の T i と A 1片を E B溶解法で溶解 （真空度 1.33 x l03pa、 出 力 80kW) して、 表 3に示す A 1含有量を有する各合金ィンゴヅ ト （直 径 105漏） をそれぞれ作製した。 E B溶解の回数は表 3に示す通りであ る。 次いで、 E B溶解により得られた各合金ィンゴッ トに、 表 3に示す 温度で 30 時間の溶体化処理を施した。 これら各合金素材に対して 1000°Cで熱間圧延を施した後、 実施例 1 と同様にして、 直径 320龍 X厚 さ lOmmの T i 一 A 1合金夕一ゲッ トをそれそれ作製した。 High purity T i and A 1 piece of dissolution in EB lysis method (degree of vacuum 1.33 x l03p a, output 80 kW) to (leakage diameter 105) each alloy Ingodzu bets with A 1 content shown in Table 3 Were prepared respectively. The number of EB dissolutions is as shown in Table 3. You. Next, each alloy ingot obtained by EB melting was subjected to a solution treatment at a temperature shown in Table 3 for 30 hours. After hot rolling at 1000 ° C for each of these alloy materials, a Ti-A1 alloy evening get with a diameter of 320 dragons and a thickness of lOmm was produced in the same manner as in Example 1. .
このようにして得た各 T i _ A l合金夕ーゲッ 卜の X線回折を実施し たところ、 いずれの X線回折パターンにも T iピークと T i 一 A 1金属 間化合物のピークしか出現していないことを確認した。 すなわち、 各 T i— A 1合金ターゲッ トは、 T i— A 1固溶体と T i 一 A 1金属間化合 物組織とからなる均一な組織を有していた。 さらに、 これら各 T i _ A 1合金ターゲッ トの A 1含有量のバラツキ、 平均酸素含有量、 酸素含有 量のバラヅキを、 前述した方法にしたがってそれぞれ測定した。 これら の測定結果を表 3に示す。 表 3  When the X-ray diffraction of each Ti_Al alloy obtained in this way was performed, only the Ti peak and the peak of the Ti-A1 intermetallic compound appeared in any of the X-ray diffraction patterns. Not sure that. That is, each Ti—A1 alloy target had a uniform structure consisting of a Ti—A1 solid solution and a Ti—A1 intermetallic compound structure. Further, the variation in the A1 content, the average oxygen content, and the variation in the oxygen content of each of these Ti_A1 alloy targets were measured in accordance with the above-described methods. Table 3 shows the measurement results. Table 3
Figure imgf000024_0001
Figure imgf000024_0001
氺 ： T A 1合金の融点に対する比率 比較例 1〜 4  氺: Ratio to melting point of T A1 alloy Comparative Examples 1-4
本発明との比較例 1 として、 緻密化焼結した T i— A 1合金素材 （焼 結体） を用いる以外は、 実施例 1と同様にして T i 一 A 1合金夕一ゲヅ ト作製した。 比較例 2および比較例 3として、 アーク溶解または E B溶 解の回数をそれぞれ 1回とする以外は、 実施例 2の試料 No.13および実 施例 3の試料 No .3 と同様にして、 T i— A 1合金夕一ゲヅ トをそれそ れ作製した。 As Comparative Example 1 with the present invention, a Ti-A1 alloy evening gate was produced in the same manner as in Example 1 except that a densified sintered Ti—A1 alloy material (sintered body) was used. did. As Comparative Examples 2 and 3, except that the number of times of the arc melting or the EB melting was set to one each, in the same manner as in Sample No. 13 of Example 2 and Sample No. 3 of Example 3, the T i—A 1 alloy evening gate Made.
さらに比較例 4として、 コールドウォール法で溶体化処理を行わない 以外は、 実施例 1の試料 No.9 と同様にして T i— A 1合金ターゲッ ト を作製した。 これら比較例 1〜4による各 T i一 A 1合金夕一ゲッ トの A 1含有量のバラツキ、 平均酸素量、 酸素量のバラヅキを、 前述した方 法にしたがってそれそれ測定した。 これらの測定結果を表 4に示す。 表 4  Further, as Comparative Example 4, a Ti—A1 alloy target was produced in the same manner as in Sample No. 9 of Example 1, except that the solution treatment was not performed by the cold wall method. The variation in the A1 content, the average oxygen content, and the variation in the oxygen content of each Ti-A1 alloy according to Comparative Examples 1 to 4 were measured in accordance with the above-described method. Table 4 shows the measurement results. Table 4
Figure imgf000025_0001
次に、 上述した実施例 1〜 3および比較例 1〜 3の各 T i一 A 1合金 ターゲッ トを用いて、 S i (100)基板上に化相スパヅ夕により T i— A 1一 N膜を 10〜； lOOnm程度の厚さで成膜した。 スパヅ夕ガスには N2 と A rの混合ガス （N2 = 3sccm, A r = 30sccm) を用い、 基板温度は 600°Cとした。 S i (100)基板には、 1%HF溶液で 3 分間表面ェヅチン グを行い、 超純水にて 30 分リ ンスオフしたものを用いた。 T i—A l —N膜を成膜した S i基板の枚数はそれそれ 500枚とした。
Figure imgf000025_0001
Next, using each Ti-A1 alloy target of Examples 1 to 3 and Comparative Examples 1 to 3 described above, Ti—A1N The film was formed to a thickness of about 10 to 100 nm. A mixed gas of N 2 and Ar (N 2 = 3 sccm, Ar = 30 sccm) was used as the gas for the sputtering, and the substrate temperature was 600 ° C. The S i (100) substrate used was a surface etched with a 1% HF solution for 3 minutes and rinsed off with ultrapure water for 30 minutes. The number of Si substrates on which the Ti—Al—N films were formed was 500 each.
このようにして成膜した各 T i—A l _N膜の結晶性を真空チャンバ 内 に 装備 し た R H E E D ( Reflection High Energy Electron Diffrection： 反射高速電子回折） により確認した。 すなわち、 RHE E Dの回折パターンからェピタキシャル膜かそうでないかを判定した。 各例でそれぞれ成膜した 500枚の S i基板について、 各 T i—A l— N 膜がェピタキシャルしているかどうかを観察した。 その結果を表 5にま とめて示す。 表 5の値は 500枚中のェピタキシャル成長した枚数をパ一 セント （％) で表したものである。 The crystallinity of each Ti-Al_N film thus formed was confirmed by RHEED (Reflection High Energy Electron Diffrection) installed in a vacuum chamber. That is, it was determined from the RHEED diffraction pattern whether the film was an epitaxy film or not. For each of the 500 S i substrates deposited in each example, each T i—A l— N It was observed whether the membrane was epitaxy. Table 5 summarizes the results. The values in Table 5 show the number of epitaxially grown sheets out of 500 sheets as a percentage (%).
次に、 上述した各 T i— A 1— N膜をバリア膜として、 その上にそれ それ P t膜を R Fマグネト口ンスパヅ夕 （基板温度 500°C) により形成 して下部電極とした。 P t膜の厚さは約 lOOnmとした。 さらに、 その上 に誘電体膜として B a T i 03 膜 （膜厚約 200ηηι) を R Fマグネ トロン スパヅ夕により形成した。 この際、 基板温度は 600°C、 スパヅ夕ガスは 02 100%で行った。 Next, each of the Ti—A 1—N films described above was used as a barrier film, and a Pt film was formed thereon using an RF magneto aperture (substrate temperature: 500 ° C.) to form a lower electrode. The thickness of the Pt film was about 100 nm. In addition, a B a T i 0 3 film as a dielectric film (thickness: about 200Itaitaiota) was formed by RF magnetic Tron Supadzu evening that. At this time, the substrate temperature was set to 600 ° C., and the temperature of the gas was 02 100%.
各 B aT i〇3 膜がェピタキシャルしているかどうかを、 T i— A 1 —N膜と同様にして観察した。 その結果を表 5に併せて示す。 表 5の値 は 500枚中のェピタキシャル成長した枚数をパーセン ト （％) で表した ものである。 さらに、 リフ トオフを用いた RFマグネトロンスパッ夕に より、 室温にて上部電極として P t膜を形成することによって、 FRA M用の薄膜キャパシ夕を作製した。 Whether each BaTi3 film was epitaxy was observed in the same manner as the Ti-A1-N film. The results are shown in Table 5. The values in Table 5 show the number of epitaxially grown sheets out of 500 sheets as a percentage (%). Furthermore, a thin film capacity for FRAM was fabricated by forming a Pt film as an upper electrode at room temperature by RF magnetron sputtering using lift-off.
表 5 Table 5
Figure imgf000027_0001
表 5から明らかのように、 実施例 1 〜 3による各スパッ夕夕一ゲッ ト を用いて成膜した T i _ A 1— N膜は、 いずれもェピタキシャル成長性 に優れ、 それに基づいて B a T i 0 3 膜についても良好にェピ夕キシャ ル成長させることが可能であることが分かる。 さらに、 実施例 1 〜 3に よる各 B a T i 0 3 膜はいずれも良好な残留分極を有していることが確 口心された。
Figure imgf000027_0001
As is evident from Table 5, the Ti_A1-N films formed by using each of the sputtering targets according to Examples 1 to 3 have excellent epitaxy growth properties, and a T i 0 3 film can be seen also favorably can be E peak evening press Le grown for. Further, in Examples 1 to 3, It has neither the B a T i 0 3 film has good residual polarization due is sure Kuchishin.
実施例 4 Example 4
高純度の T iと A 1片をコールドウオール溶解法で溶解して、 A 1含 有量が 9原子％の合金インゴッ ト （直径 75〜； 105mm) を複数作製した。 次に、 これら合金イ ンゴッ ト に対して 1000 °Cで熱間圧延 （加工率 80% ) を施した後、 表 2に示す温度でそれそれ 1時間のァニール処理を 施して再結晶化させた。  High purity Ti and A1 pieces were melted by the cold wall melting method to produce a plurality of alloy ingots (diameter: 75 to 105 mm) with A1 content of 9 atomic%. Next, these alloy ingots were subjected to hot rolling (working rate 80%) at 1000 ° C, and then annealed for 1 hour at the temperatures shown in Table 2 for recrystallization. .
これら各合金ィンゴッ トを研削、 研磨した後、 それそれ A 1製バヅキ ングプレートとホッ トプレスにより拡散接合し、 さらに機械加工を施す ことによって、 直径 320mm x厚さ 10mm の T i— A 1合金夕一ゲヅ トを それそれ作製した。  Each of these alloy ingots is ground and polished, and then diffusion bonded by a hot press and an A1 backing plate, and further machined to produce a Ti-A1 alloy with a diameter of 320 mm and a thickness of 10 mm. I made one gate each.
このようにして得た各 T i一 A 1合金夕一ゲッ トの平均結晶粒径およ びそのバラツキを、 前述した方法にしたがって測定した。 これらの測定 結果を表 6に示す。 なお、 各 T i一 A 1合金夕ーゲッ トは、 実施例 1 と 同様に、 T i— A 1固溶体と T i一 A 1金属間化合物組織とからなる均 —な組織を有していた。 さらに、 A 1含有量のバラヅキについても、 実 施例 1 と同様であった。  The average crystal grain size and the variation of each Ti-A1 alloy thus obtained were measured according to the method described above. Table 6 shows the results of these measurements. Each Ti-A1 alloy target had a uniform structure consisting of a Ti-A1 solid solution and a Ti-A1 intermetallic compound structure, as in Example 1. Further, the variation of the A1 content was the same as in Example 1.
上述した各 T i - A 1合金夕ーゲヅ トをそれそれ用いて、 S i ( 100 ) 基板上に化相スパッ夕により T i一 A 1— N膜を 10〜： lOOnm程度の厚さ で成膜した。 T i— A 1—N膜の成膜条件は上述した通りである。 S i 基板の枚数はそれそれ 500枚とした。  Using each of the Ti-A1 alloy gates described above, a Ti-A1-N film is formed on the Si (100) substrate by chemical phase sputtering to a thickness of about 10 to 100 nm. Filmed. The film forming conditions for the Ti—A 1—N film are as described above. The number of Si substrates was 500 each.
このようにして得た各 T i一 A 1—N膜中に存在する、 大きさ l〃m 以上のダス ト数をパーティクルカウン夕で測定した。 その結果を表 6に 併せて示す。 表 6のダスト数は 500枚の平均値である。 なお、 各膜の結 晶性を真空チヤンバ内に装備した R H E E Dにより確認したところ、 ェ ピ夕キシャル膜の回折パターンであり、 かつス トリークが観察され、 平 滑なェピタキシャル膜が形成されていることを確認した。 表 6 The number of dust having a size of l〃m or more present in each Ti-A1-N film thus obtained was measured by particle counting. The results are shown in Table 6. The number of dust in Table 6 is the average value of 500 pieces. The crystallinity of each film was confirmed by RHEED installed in the vacuum chamber. It was a diffraction pattern of the epitaxial film, and a streak was observed, confirming that a smooth epitaxial film was formed. Table 6
Figure imgf000029_0001
表 6から明らかなように、 実施例 4による各スパッ夕夕一ゲッ トを用 いて成膜した T i - A 1— N膜は、 いずれもダスト数が少ないことが分 かる。 従って、 このような T i一 A l— N膜をバリア膜として使用する ことによって、 各種デバイスの製造歩留りを向上させることができる。 産業上の利用可能性
Figure imgf000029_0001
As is clear from Table 6, it can be seen that the Ti-A1-N films formed by using each of the sputtering targets according to Example 4 have a small number of dusts. Therefore, by using such a Ti-Al-N film as a barrier film, the production yield of various devices can be improved. Industrial applicability
以上の実施形態からも明らかなように、 本発明のスパッ夕夕一ゲッ ト によれば、 パリァ膜としての特性や品質に優れる T i一 A 1— N膜など を再現性よく形成することが可能となる。 従って、 このような T i— A 1—N膜からなるバリア膜を使用することによって、 各種電子部品の特 性や歩留りの向上を図ることが可能となる。 本発明のバリア膜は、 特に 誘電体膜としてぺロプスカイ ト型酸化物膜を用いた F R A Mや D R A M に好適である。  As is clear from the above embodiments, according to the sputtering apparatus of the present invention, it is possible to form a Ti-A1-N film having excellent characteristics and quality as a parier film with good reproducibility. It becomes possible. Therefore, by using such a barrier film composed of the Ti—A 1—N film, it is possible to improve the characteristics and yield of various electronic components. The barrier film of the present invention is particularly suitable for FRAM and DRAM using a perovskite oxide film as a dielectric film.

Claims

請 求 の 範 囲 The scope of the claims
1 . T i - A 1合金により構成されたスパッ夕夕一ゲッ トであって、 前記 T i 一 A 1合金中の A 1は、 T i中に固溶した状態、 および T i と金属間化合物を形成した状態の少なく とも一方の状態で存在してお り、 かつ夕一ゲヅ ト全体としての A 1含有量のバラヅキが 10 %以内で あることを特徴とするスパッ夕夕一ゲッ ト。 1. A spatter alloy made of a Ti-A1 alloy, wherein A1 in the Ti-A1 alloy is in a solid solution state in Ti, and between Ti and a metal. A sputter bath characterized by being present in at least one of the states in which the compound is formed, and having a variation in the A1 content of the whole bath within 10%. .
2 . 請求項 1記載のスパッ夕夕一ゲヅ トにおいて、 2. In the gate of claim 1 described in claim 1,
前記 T i _ A 1合金は 1〜 3 0原子％の範囲の A 1を含有することを 特徴とするスパッ夕夕一ゲッ ト。  The sputtering target according to claim 1, wherein the Ti_A1 alloy contains A1 in a range of 1 to 30 atomic%.
3 . 請求項 1記載のスパッ夕夕一ゲッ トにおいて、  3. In the spaghetti described in claim 1,
前記 T i - A 1合金は 5 o o / m以下の平均結晶粒径を有することを特 徴とするスパッ夕夕ーゲッ ト。  The sputtering target, wherein the Ti-A1 alloy has an average crystal grain size of 5 oo / m or less.
4 . 請求項 3記載のスパッ夕夕ーゲッ トにおいて、  4. In the spaghetti described in claim 3,
夕一ゲヅ ト全体としての結晶粒径のバラヅキが 3 0 %以内であること を特徴とするスパッ夕夕ーゲッ ト。  A sputter target, wherein the variation in the crystal grain size as a whole is within 30%.
5 . 請求項 1記載のスパヅ夕夕一ゲッ トにおいて、  5. In the spa, evening and evening get described in claim 1,
前記 T i— A 1合金の平均酸素含有量が 900ppm以下であることを 特徴とするスパッ夕夕ーゲッ ト。  The sputter target, wherein the Ti—A1 alloy has an average oxygen content of 900 ppm or less.
6 . 請求項 5記載のスパヅ夕ターゲッ トにおいて、 6. In the spa target according to claim 5,
夕一ゲッ ト全体としての酸素含有量のバラツキが 3 0 %以内であるこ とを特徴とするスパッ夕夕ーゲッ ト。  A sputter set, characterized in that the variation in the oxygen content as a whole is within 30%.
7 . 請求項 1記載のスパッ夕夕一ゲッ トにおいて、  7. In the spaghetti set described in claim 1,
前記スパヅ夕夕一ゲヅ トはバッキングプレートと接合されていること を特徴とするスパッ夕ターゲッ ト。  A spaghetti target, wherein the spa evening and evening gate is joined to a backing plate.
8 . T i 一 A 1合金により構成されたスパヅ夕夕一ゲヅ トであって、 前記 T i— A 1合金中の A 1は、 T i中に固溶した状態、 および T i と金属間化合物を形成した状態の少なく とも一方の状態で存在してお り、 かつ前記 T i— A 1合金の平均結晶粒径が 500 zm以下であると共 に、 夕一ゲッ ト全体としての結晶粒径のバラヅキが 3 0 %以内であるこ とを特徴とするスパッ夕夕ーゲッ ト。 8. A spa evening and evening gate made of Ti-A1 alloy, A 1 in the Ti—A 1 alloy exists in a solid solution state in Ti and in at least one of a state in which an intermetallic compound is formed with Ti, and — A sputter target, wherein the average grain size of the A1 alloy is 500 zm or less and the variation of the grain size as a whole is within 30%.
9 . 請求項 8記載のスパッ夕夕一ゲッ トにおいて、  9. In the spaghetti set described in claim 8,
前記 T i _ A l合金は 1 ~ 3 0原子％の範囲の A 1を含有することを 特徴とするスパッ夕夕一ゲッ ト。  The sputtering target according to claim 1, wherein the Ti_Al alloy contains Al in a range of 1 to 30 atomic%.
1 0 . 請求項 8記載のスパヅ夕夕一ゲヅ 卜において、  10. In the spa evening and evening gate described in claim 8,
前記スパヅ夕夕一ゲッ トはバヅキングプレートと接合されていること を特徴とするスパッ夕ターゲッ ト。  The spaghetti target, wherein the spa evening and evening get is joined to a backing plate.
1 1 . 請求項 1記載のスパヅ夕夕一ゲッ トを用いて成膜してなる T i 一 A 1—N膜を具備することを特徴とするバリァ膜。  11. A barrier film, comprising a Ti-A1-N film formed by using the spa device according to claim 1.
1 2 . 請求項 1 1記載のバリァ膜において、  12. The barrier film according to claim 11, wherein
前記 T i— A 1—N膜は半導体基板に対するバリァ材として用いられ ることを特徴とするバリア膜。  The Ti-A1-N film is used as a barrier material for a semiconductor substrate.
1 3 . 請求項 8記載のスパッ夕夕一ゲヅ トを用いて成膜してなる T i 一 A 1— N膜を具備することを特徴とするバリァ膜。  13. A barrier film, comprising: a Ti-A1-N film formed by using the sputter gate according to claim 8.
1 4 . 請求項 1 3記載のバリア膜において、  14. The barrier film according to claim 13,
前記 T i— A 1—N膜は半導体基板に対するバリァ材として用いられ ることを特徴とするバリア膜。  The Ti-A1-N film is used as a barrier material for a semiconductor substrate.
1 5 . 請求項 1 1記載のバリア膜を具備することを特徴とする電子部 15. An electronic unit comprising the barrier film according to claim 11.
ΠΡ o ΠΡ o
1 6 . 請求項 1 5記載の電子部品において、  16. The electronic component according to claim 15,
半導体基板と、 前記半導体基板上に形成された前記バリア膜と、 前記 バリァ膜上に形成された薄膜キャパシ夕とを具備することを特徴とする 電子部口 CI o A semiconductor substrate; a barrier film formed on the semiconductor substrate; and a thin film capacitor formed on the barrier film. Electronics department CI o
1 7 . 請求項 1 3記載のバリア膜を具備することを特徴とする電子部 α  17. An electronic part α comprising the barrier film according to claim 13.
ΠΡ ο .  ΠΡ ο.
1 8 . 請求項 1 7記載の電子部品において、  18. The electronic component according to claim 17,
半導体基板と、 前記半導体基板上に形成された前記バリア膜と、 前記 バリァ膜上に形成された薄膜キャパシ夕とを具備することを特徴とする 電子部  An electronic part comprising: a semiconductor substrate; the barrier film formed on the semiconductor substrate; and a thin film capacitor formed on the barrier film.
PCT/JP2001/003379 2000-04-20 2001-04-20 Sputter target, barrier film and electronic component WO2001081650A1 (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
JP2001578717A JP5065565B2 (en) 2000-04-20 2001-04-20 Sputter target
US10/257,404 US6750542B2 (en) 2000-04-20 2001-04-20 Sputter target, barrier film and electronic component
KR10-2002-7014056A KR100504062B1 (en) 2000-04-20 2001-04-20 Sputter target, barrier film and electronic component

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2000-119539 2000-04-20
JP2000119539 2000-04-20

Publications (1)

Publication Number Publication Date
WO2001081650A1 true WO2001081650A1 (en) 2001-11-01

Family

ID=18630502

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2001/003379 WO2001081650A1 (en) 2000-04-20 2001-04-20 Sputter target, barrier film and electronic component

Country Status (5)

Country Link
US (1) US6750542B2 (en)
JP (2) JP5065565B2 (en)
KR (1) KR100504062B1 (en)
TW (1) TWI256420B (en)
WO (1) WO2001081650A1 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007250632A (en) * 2006-03-14 2007-09-27 Seiko Epson Corp Ferroelectric memory device, and manufacturing method of ferroelectric memory device
JP2007250634A (en) * 2006-03-14 2007-09-27 Seiko Epson Corp Ferroelectric memory device, and manufacturing method of ferroelectric memory device

Families Citing this family (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7427538B2 (en) * 2002-08-16 2008-09-23 Intel Corporation Semiconductor on insulator apparatus and method
JP3873935B2 (en) * 2003-06-18 2007-01-31 セイコーエプソン株式会社 Ferroelectric memory device
KR100633330B1 (en) * 2004-07-30 2006-10-12 주식회사 하이닉스반도체 Method for fabricating capacitor in semiconductor device
KR100842897B1 (en) * 2007-01-29 2008-07-03 삼성전자주식회사 Structure of ferroelectric media for ferroelectric hdd and method of manufacture thereof
JP4320679B2 (en) * 2007-02-19 2009-08-26 セイコーエプソン株式会社 Method for manufacturing ferroelectric memory device
JP5886473B2 (en) * 2013-03-19 2016-03-16 Ｊｘ金属株式会社 Ti-Al alloy sputtering target
WO2015186413A1 (en) 2014-06-02 2015-12-10 三菱日立ツール株式会社 Rigid coating film, member coated with rigid coating film, production processes therefor, and target for use in producing rigid coating film
JP6574714B2 (en) * 2016-01-25 2019-09-11 株式会社コベルコ科研 Wiring structure and sputtering target
JP6440866B2 (en) * 2016-03-25 2018-12-19 Ｊｘ金属株式会社 Ti-Nb alloy sputtering target and manufacturing method thereof

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH06280009A (en) * 1993-03-30 1994-10-04 Mitsubishi Materials Corp Target for sputtering and its production
US5456815A (en) * 1993-04-08 1995-10-10 Japan Energy Corporation Sputtering targets of high-purity aluminum or alloy thereof
JPH08134635A (en) * 1994-11-15 1996-05-28 Kobe Steel Ltd Aluminum-titanium alloy target materia for dry-process vapor deposition
JP2000100755A (en) * 1998-09-25 2000-04-07 Mitsubishi Materials Corp Ti-Al ALLOY SPUTTERING TARGET FOR FORMING BARRIER FILM OF SEMICONDUCTOR DEVICE
JP2000328242A (en) * 1999-05-25 2000-11-28 Kobe Steel Ltd Ti-al alloy sputtering target and its production

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH06322530A (en) 1993-05-10 1994-11-22 Vacuum Metallurgical Co Ltd Target for sputtering
JPH116056A (en) * 1997-06-12 1999-01-12 Toshiba Tungaloy Co Ltd Target containing intermetallic compound, and manufacture of hard covered member using it
JP3367600B2 (en) * 1998-06-08 2003-01-14 シャープ株式会社 Method of manufacturing dielectric thin film element
JP2000273623A (en) 1999-03-29 2000-10-03 Japan Energy Corp Ti-Al ALLOY SPUTTERING TARGET

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH06280009A (en) * 1993-03-30 1994-10-04 Mitsubishi Materials Corp Target for sputtering and its production
US5456815A (en) * 1993-04-08 1995-10-10 Japan Energy Corporation Sputtering targets of high-purity aluminum or alloy thereof
JPH08134635A (en) * 1994-11-15 1996-05-28 Kobe Steel Ltd Aluminum-titanium alloy target materia for dry-process vapor deposition
JP2000100755A (en) * 1998-09-25 2000-04-07 Mitsubishi Materials Corp Ti-Al ALLOY SPUTTERING TARGET FOR FORMING BARRIER FILM OF SEMICONDUCTOR DEVICE
JP2000328242A (en) * 1999-05-25 2000-11-28 Kobe Steel Ltd Ti-al alloy sputtering target and its production

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007250632A (en) * 2006-03-14 2007-09-27 Seiko Epson Corp Ferroelectric memory device, and manufacturing method of ferroelectric memory device
JP2007250634A (en) * 2006-03-14 2007-09-27 Seiko Epson Corp Ferroelectric memory device, and manufacturing method of ferroelectric memory device
JP4613857B2 (en) * 2006-03-14 2011-01-19 セイコーエプソン株式会社 Ferroelectric memory device and method for manufacturing ferroelectric memory device

Also Published As

Publication number Publication date
KR100504062B1 (en) 2005-07-27
KR20030032937A (en) 2003-04-26
US20030116849A1 (en) 2003-06-26
JP2012072496A (en) 2012-04-12
TWI256420B (en) 2006-06-11
JP5065565B2 (en) 2012-11-07
US6750542B2 (en) 2004-06-15
JP5487182B2 (en) 2014-05-07

Similar Documents

Publication Publication Date Title
JP5487182B2 (en) Sputter target
EP0855738B1 (en) Method of depositing a platinum film for capacitor electrode
JP2974006B2 (en) Method of forming preferentially oriented platinum thin film using oxygen and device manufactured by the method
JP3445276B2 (en) Mo-W target for wiring formation, Mo-W wiring thin film, and liquid crystal display device using the same
US20040092107A1 (en) Perovskite-type material forming methods, capacitor dielectric forming methods, and capacitor constructions
JP4228560B2 (en) Capacitor element and manufacturing method thereof
KR101767242B1 (en) Single crystalline metal films containing hydrogen atom or hydrogen ion and manufacturing method thereof
EP1099777A1 (en) Sputter target
JPH08316233A (en) Manufacture of semiconductor device
JP4342639B2 (en) Sputtering target and electrode film manufacturing method
KR19980070383A (en) A method for forming a platinum thin film having an antioxidant function on a substrate and an electronic device having a platinum thin film formed by the method
CN1659304A (en) Thin films and methods for forming thin films utilizing ECAE-targets
JP5526072B2 (en) Sputtering target and Ti-Al-N film and electronic component manufacturing method using the same
JP2000355760A (en) Sputtering target, barrier film and electronic parts
JP5622914B2 (en) Sputtering target manufacturing method, Ti-Al-N film manufacturing method, and electronic component manufacturing method
JP4820507B2 (en) Sputtering target and manufacturing method thereof, and Ti-Al-N film and electronic component manufacturing method using the same
JP5389093B2 (en) Sputtering target and Ti-Al-N film and electronic component manufacturing method using the same
JPH09331034A (en) Oxide electrode film forming method
Lee et al. Microstructures and electrical resistivities of the RuO2 electrode on SiO2/Si annealed in the oxygen ambient
JP2003318369A (en) Semiconductor device and method of manufacturing the same
Pak et al. Fabrications and electrical properties of ferroelectric Bi3. 25La0. 75Ti3O12 thin films using a indium–tin-oxide conductive layer as the bottom electrode
Suh et al. Crystallization of amorphous WN x films
JPH05291560A (en) Barrier metal of semiconductor device
JP2024046741A (en) Highly crystalline barium titanate film, its preparation method and application
JP3234978B2 (en) Method for forming diffusion barrier layer of semiconductor device

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): JP KR US

DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
ENP Entry into the national phase

Ref country code: JP

Ref document number: 2001 578717

Kind code of ref document: A

Format of ref document f/p: F

WWE Wipo information: entry into national phase

Ref document number: 1020027014056

Country of ref document: KR

WWE Wipo information: entry into national phase

Ref document number: 10257404

Country of ref document: US

WWP Wipo information: published in national office

Ref document number: 1020027014056

Country of ref document: KR

WWG Wipo information: grant in national office

Ref document number: 1020027014056

Country of ref document: KR